TU IOST | Physics
The SI unit of force is the
Answer: newton
Starter practice set, Q32: explanation →The approximate acceleration due to gravity at Earth's surface is
Answer: 9.8 m/s^2
Starter practice set, Q33: explanation →According to Ohm's law, V equals
Answer: IR
Starter practice set, Q34: explanation →Light travels fastest in
Answer: vacuum
Starter practice set, Q35: explanation →The SI unit of power is the
Answer: watt
Starter practice set, Q36: explanation →Frequency is measured in
Answer: hertz
Starter practice set, Q37: explanation →A body starts from rest and moves with uniform acceleration of 2 m/s^2. Distance covered in 5th second is:
Answer: 9 m
Starter practice set, Q38: explanation →The SI unit of magnetic flux is:
Answer: Weber
Starter practice set, Q39: explanation →A projectile is fired at 45 degrees for maximum range. If speed is 20 m/s, the range on level ground is (g=10 m/s^2):
Answer: 40 m
Starter practice set, Q40: explanation →Which of the following is a vector quantity?
Answer: Momentum
Starter practice set, Q41: explanation →The escape velocity from Earth's surface is approximately:
Answer: 11.2 km/s
Starter practice set, Q42: explanation →Two resistors of 4 ohm and 6 ohm are connected in parallel. Equivalent resistance is:
Answer: 2.4 ohm
Starter practice set, Q43: explanation →The phenomenon of bending of light around obstacles is called:
Answer: Diffraction
Starter practice set, Q44: explanation →A capacitor of 10 microF is charged to 100 V. The energy stored is:
Answer: 0.05 J
Starter practice set, Q45: explanation →According to Bohr's model, the radius of the first orbit of hydrogen atom is:
Answer: 0.53 angstrom
Starter practice set, Q46: explanation →The work function of a metal is 2 eV. The threshold frequency is closest to (h=6.63e-34 Js):
Answer: 4.8x10^14 Hz
Starter practice set, Q47: explanation →In simple harmonic motion, the acceleration is maximum at:
Answer: Extreme position
Starter practice set, Q48: explanation →The temperature at which Celsius and Fahrenheit scales give the same reading is:
Answer: -40
Starter practice set, Q49: explanation →The unit of specific heat capacity is:
Answer: J/kg-K
Starter practice set, Q50: explanation →A convex lens of focal length 20 cm forms a real image at 60 cm. Object distance is:
Answer: 30 cm
Starter practice set, Q51: explanation →Which law states that current is directly proportional to potential difference at constant temperature?
Answer: Ohm's law
Starter practice set, Q52: explanation →The de Broglie wavelength of a particle is inversely proportional to its:
Answer: Momentum
Starter practice set, Q53: explanation →Half life of a radioactive substance is 10 days. After 30 days, fraction remaining is:
Answer: 1/8
Starter practice set, Q54: explanation →The number of significant figures in 0.00520 is:
Answer: 3
Starter practice set, Q55: explanation →A wire is stretched to double its length. Its resistance becomes:
Answer: Four times
Starter practice set, Q56: explanation →The centripetal acceleration of a body moving in a circle of radius 2 m with speed 4 m/s is:
Answer: 8 m/s^2
Starter practice set, Q57: explanation →The equivalent resistance between the points $x$ and $y$ is [Figure: bridge network of 10, 20, 10 ohm in series along the middle with 10 ohm across the first two and 10 ohm across the last two]
Answer: $10\ \Omega$
2079 paper, Q18: explanation →A $100,\text{W}/220,\text{V}$ bulb is used in a line of $440,\text{V}$. Its power will be
Answer: $400,\text{W}$
2078 paper, Q66: explanation →A heater coil is cut into two equal parts and only one part is used in the heater. How will the heat generated vary?
Answer: doubled
2077 paper, Q67: explanation →A 50 V battery is connected across 10 ohm resistor. The current in the circuit is 4.5 Ampere. The internal resistance of the battery should be
Answer: 1.1 Ohm
2077 paper, Q68: explanation →The energy dissipation in a resistor of resistance R in time t is E, then the value of current flowing in the resistance will be
Answer: $\sqrt{\frac{E}{Rt}}$
2076 paper, Q43: explanation →A wire of resistance $12\ \Omega$ is bent to form a circle. The effective resistance between the two points on any diameter of circle is
Answer: $3\ \Omega$
2075 paper, Q42: explanation →The resistance of an ideal ammeter is
Answer:
2075 paper, Q43: explanation →Kirchhoff's voltage law is based on the principle of conservation of
Answer: energy
2073 paper, Q66: explanation →The radius of a copper wire carrying a current is doubled, the drift velocity of electrons will
Answer: Decreases four times
2072 paper, Q66: explanation →A 25 W, 120 V lamp and 100 W, 120 V lamp are connected in series across a 120 V line. Which lamp will burn more brightly?
Answer: 25 W, 120 V
2072 paper, Q67: explanation →Two wires of same material have lengths $L$ and $2L$ and cross section areas $4A$ and $A$ respectively. The ratio of their specific resistances would be
Answer: 1:1
2071 paper, Q70: explanation →Three equal resistors each of resistance $r$ are connected to form a triangle. The equivalent resistance across any two corners of the triangle is
Answer: $2r/3$
2070 paper, Q65: explanation →The resistances of two lamps are in the ratio $1:2$. Their wattage will be in the ratio of
Answer: $2:1$
2070 paper, Q66: explanation →Watt per ampere is the unit of
Answer: electric potential
2069 paper, Q64: explanation →Two wires A and B of equal radii are drawn from the same material. Their lengths are 1m and 2m respectively. The resistivity of A is
Answer: equal to that of B
2069 paper, Q65: explanation →A cell of $emf\ X$ if connected across a resistance R. The potential difference across the wire is measured as Y. The internal resistance of the cell should be
Answer: $(X-Y)R/Y$
2069 paper, Q67: explanation →The horizontal range is $4\sqrt{3}$ times the maximum height in a projectile motion. The angle of projection is
Answer: $30^\circ$
2081 paper, Q18: explanation →A stone is dropped into a well 78.4 m deep. The splash sound is noticed after (velocity of sound in air is 350 m/s)
Answer: $4.2,s$
2081 paper, Q24: explanation →Two balls of the same mass are shot upwards one after another at an interval of 2 seconds along the same vertical line with the same initial velocity of $40,m/s$. They will collide at a height of
Answer: $75,m$
2080 paper, Q28: explanation →A cricket ball is hit at $45^\circ$ to horizontal with a kinetic energy $K$. The kinetic energy of ball at highest point of path is
Answer: $K/2$
2080 paper, Q29: explanation →A stone is dropped from a height of 45 m. The distance travelled by it during its last second is
Answer: 25 m
2079 paper, Q3: explanation →Stars appear to move from east to west because
Answer: the earth rotates from west to east
2078 paper, Q53: explanation →A bullet fired into a fixed target loses half of its velocity after penetrating 3 cm. The further distance travelled before the rest is
Answer: 1 cm
2077 paper, Q52: explanation →The horizontal range is $4\sqrt3$ times the maximum height in a projectile motion. The angle of projectile is
Answer: $30^0$
2077 paper, Q53: explanation →The displacement of a particle moving along x-axis is given by $x=a+bt+ct^2$. The acceleration of the particle is
Answer: 2c
2076 paper, Q26: explanation →A projectile goes farthest away from the earth when the angle of projection is
Answer: $90^\circ$
2074 paper, Q52: explanation →If initial velocity of a projectile is doubled, the maximum range will be
Answer: 4 times
2073 paper, Q54: explanation →A river is flowing west to east at a speed of 5 m/min. A man on the south bank of the river, capable of swimming at 10 m/min in still water, wants to swim across the river by the shortest path. He should swim in the direction
Answer: $30^\circ$ West of North
2072 paper, Q53: explanation →A stone is thrown vertically upward with a speed $u$ from the top of a tower and reaches the ground with a speed $3u$. The height of the tower is
Answer: $\frac{4u^2}{g}$
2070 paper, Q52: explanation →A train of length 600 m is travelling with a velocity of 64 km/hr. The time taken by the train to cross clearly a bridge of 1 km will be
Answer: 1.5 min
2069 paper, Q52: explanation →Time of flight T of a projectile is related to the horizontal range R by an equation $gT^2=2R$. The angle of projection (in degrees) is
Answer: $45^0$
2069 paper, Q73: explanation →The quantity having no dimension is
Answer: Angle
2081 paper, Q16: explanation →Joule x second is the unit of
Answer: Angular momentum
2080 paper, Q26: explanation →A quantity $x$ is related by $x=\frac{\pi}{3}(a^{2}-b^{2})h$ where $a$, $b$ and $h$ are lengths. Then $x$ is
Answer: volume
2079 paper, Q1: explanation →The velocity of a body is given by $v=\frac{b}{t}+ct^2+dt^3$. The dimensional formula of $c$ is
Answer: $[M^0LT^{-3}]$
2078 paper, Q51: explanation →Which of the following pair have the same dimension?
Answer: $L/R$ and $CR$
2077 paper, Q51: explanation →The ratio of tension to surface tension has dimension of
Answer: $[L]$
2075 paper, Q26: explanation →The order of magnitude of the radius of an atom is
Answer: $10^{-10}$ m
2074 paper, Q51: explanation →In the gas equation $\left(p+\frac{a}{V^2}\right)(V-b)=RT$, the dimensions of 'a' are
Answer: $ML^5T^{-2}$
2073 paper, Q51: explanation →The number of significant figures in 1400 are
Answer: 2
2073 paper, Q52: explanation →Dimension of surface energy is
Answer: $[M^1L^0T^{-2}]$
2072 paper, Q54: explanation →The dimensions of $(h/e)$ are same as that of
Answer: Magnetic flux
2071 paper, Q51: explanation →The number of significant figures in $0.0030\times10^{11},m$ are
Answer:
2071 paper, Q52: explanation →The dimensional formula for potential difference is
Answer: $[ML^2T^{-3}I^{-1}]$
2070 paper, Q51: explanation →Which one of the following pairs of physical quantities has the same dimension?
Answer: Work and energy
2069 paper, Q53: explanation →The speed of electron in first Bohr orbit of Hydrogen atom is $v$. The speed of electron in the first excited state of doubly ionized Lithium atom is
Answer:
2080 paper, Q45: explanation →Which series of Hydrogen atom lies in the infrared region?
Answer: Pfund
2079 paper, Q23: explanation →The de-Broglie wavelength of an electron in $n^{th}$ Bohr orbit is related to the radius R of the orbit as,
Answer: $n\lambda=2\pi R$
2076 paper, Q47: explanation →Which of the following electronic transitions of the hydrogen atom gives an absorption line of highest frequency?
Answer: $n=1$ to $n=2$
2076 paper, Q48: explanation →According to Bohr's model of the H atom, the radius of the stationary orbit characterized by the principal quantum number $n$ is proportional to
Answer: $n^2$
2074 paper, Q74: explanation →The black body emits
Answer: continuous spectrum
2073 paper, Q60: explanation →In which region of electromagnetic spectrum does the Lyman series of H atom lie?
Answer: Ultraviolet
2073 paper, Q75: explanation →The angular momentum of electron in the hydrogen atom in the ground state is
Answer: $h/2\pi$
2072 paper, Q72: explanation →The kinetic energy of a particle is doubled, de Broglie wavelength becomes
Answer: $1/\sqrt2$ times
2072 paper, Q74: explanation →Electrons in the atoms are held due to
Answer: Coulomb forces
2071 paper, Q72: explanation →Which series of H atom lies in visible region?
Answer: Balmer
2071 paper, Q73: explanation →Rydberg constant is
Answer: Is different for lighter elements but same for heavier elements.
2071 paper, Q75: explanation →A particle of mass $10^{-31}$ kg is moving with a speed of $10^5$ m/s. The de Broglie wavelength of the particle is
Answer: $6.63\times10^{-8}$ m
2070 paper, Q69: explanation →The ratio of wavelength of the first line of Lyman series to the first line of Balmer series is
Answer: 5:27
2069 paper, Q68: explanation →In equation $\vec F=q(\vec v\times\vec B)$ the quantity $\vec F$ is
Answer: Perpendicular to both $\vec v$ and $\vec B$
2080 paper, Q27: explanation →Two parallel wires carrying currents in the same direction attract each other because of
Answer: Magnetic forces between them
2080 paper, Q40: explanation →A free charged particle moves through a magnetic field. The particle may undergo a change in
Answer: direction of motion
2080 paper, Q44: explanation →A magnetic needle kept in a non-uniform magnetic field. It experiences
Answer: Force and a torque
2079 paper, Q19: explanation →The charge in uniform motion produces
Answer: both electric and magnetic field
2078 paper, Q63: explanation →The angle of dip is the angle
Answer: between earth's magnetic field's direction and horizontal direction
2078 paper, Q70: explanation →A magnetic needle kept in a high-uniform magnitude field. It experiences
Answer: a torque but not a force
2077 paper, Q69: explanation →The angle between geographical and magnetic meridian is called
Answer: angle of declination
2076 paper, Q41: explanation →A charged particle moves along the axis of a current carrying solenoid. It experiences
Answer: no force
2076 paper, Q42: explanation →A $10$ eV electron is circulating in a plane at right angles to a uniform field of magnetic induction $10^{-4}$ T. The orbital radius of the electron is
Answer: cm
2075 paper, Q44: explanation →A charged particle enters in a strong magnetic field. Then its kinetic energy
Answer: remains constant
2073 paper, Q67: explanation →The magnetic field induction inside a long solenoid is
Answer: $\mu_0ni$
2071 paper, Q71: explanation →A charged particle is undergoing a circular motion in a uniform magnetic field. The time period is independent of
Answer: speed
2069 paper, Q71: explanation →The critical angle of light passing from glass to air is minimum for
Answer: violet
2081 paper, Q23: explanation →A microscope is focused on an 'ink mark'. A glass plate is placed over the spot. In order to focus the spot, microscope is to be raised 1 m. In order to focus scratch on upper surface it must be raised 2 m further. The refractive index of glass is
Answer: 1.50
2080 paper, Q35: explanation →A completely transparent material will be invisible in vacuum when refractive index $\mu$ is
Answer: unity
2079 paper, Q14: explanation →The path of a ray of light coming from air passing through a rectangular glass slab traced by four students is shown as A, B, C and D in the figure. Which one of them is correct? [Figure: four slabs with ray paths A, B, C, D; in A the ray goes straight on, in B it bends toward the normal inside and emerges parallel to the incident ray but shifted, in C and D it emerges at a different angle.]
Answer: B
2078 paper, Q61: explanation →If the critical angle for a material placed in air is $30^\circ$, the refractive index will be
Answer: 2
2074 paper, Q65: explanation →On heating a liquid, the refractive index generally
Answer: decreases
2074 paper, Q67: explanation →A ray of light in air enters a glass slab. Its
Answer: wave length decreases
2072 paper, Q61: explanation →The refractive index of air with respect to glass is $2/3$. The refractive index of diamond with respect to air is $12/5$. Then the refractive index of glass with respect to diamond will be
Answer:
2070 paper, Q61: explanation →Light of wavelength $7200$ Å in air has a wavelength in glass equal to (refractive index of glass with respect to air $=1.5$)
Answer: 4800 Å
2070 paper, Q63: explanation →The critical angle of glass water interface is
Answer: $\sin^{-1}\left(\frac89\right)$
2069 paper, Q59: explanation →Light travels through a glass plate of thickness t and refractive index n. If C is the velocity of light in vacuum, the time taken by light to travel this thickness is
Answer: $\frac{nt}{c}$
2069 paper, Q61: explanation →Two lenses of power $+3$ D and $-7$ D are placed in contact. The equivalent focal length of the combination will be
Answer: -25cm
2081 paper, Q27: explanation →Decrease in aperture of a lens changes
Answer: Intensity of the image
2080 paper, Q36: explanation →The image of a distant object formed by a far sighted person is
Answer: behind the retina
2078 paper, Q62: explanation →The focal length of a convex lens is
Answer: Maximum for red color
2076 paper, Q35: explanation →Two lenses of power $5$D and $-7.5$D are placed in contact. The equivalent focal length of the combination will be
Answer: cm
2075 paper, Q37: explanation →The length of a microscope is $14$ cm and the magnifying power is $25$ for relaxed eye. The focal length of eyepiece is $5$ cm. The distance of object from objective is
Answer: cm
2075 paper, Q38: explanation →A person cannot see objects clearly beyond 50 cm. The power of the lens to correct the vision is
Answer: -2 D
2073 paper, Q63: explanation →A convex lens is immersed in water. Compared to its power in air, the power in water will
Answer: Decrease for all colors
2072 paper, Q63: explanation →A double convex air bubble in a glass sheet would behave as a
Answer: Divergent lens
2071 paper, Q65: explanation →The focal length of a double convex lens for which the radius of curvature of each surface is $R$ will be ($\mu=1.5$)
Answer:
2070 paper, Q62: explanation →A myopic eye cannot see object beyond 1.5 m. What power of lens will be required to correct this defect of vision?
Answer: -0.66 D
2069 paper, Q58: explanation →A nuclear reactor has a power of 10 kW. If the energy per fission is 200 MeV then the number of fissions per second is
Answer: $5\times10^{14}$
2081 paper, Q35: explanation →The half-life of a radioactive sample is 10 years. It means the mean life is
Answer: 14.43 years
2081 paper, Q36: explanation →A GM counter gives $82,counts/sec$. After $210,seconds$ the count rate decreased to $19,counts/sec$. The background count is $10,counts/sec$, then the half life of the source is
Answer: $70,s$
2080 paper, Q48: explanation →The half-life of a radioactive sample is 10 years. Its mean life is
Answer: 14.43 years
2077 paper, Q74: explanation →The half-life of a radioactive isotope is 5 yrs. The fraction of atoms decayed in this substance after 15 years will be
Answer: $\frac78$
2076 paper, Q49: explanation →What are -rays?
Answer: Charge particle emitted by nucleus
2076 paper, Q50: explanation →When a radioactive element emits a $\beta$-particle the mass number of the atom
Answer: remains the same
2073 paper, Q70: explanation →Half-life and mean life of a radioactive element are related. Choose correct answer from the following:
Answer: half-life is less than the mean life
2072 paper, Q75: explanation →The half-life of a substance is 1600 years. The mean life is
Answer: 2309 yrs
2071 paper, Q74: explanation →The mass of an -particle is
Answer: Less than the sum of masses of 2 protons and 2 neutrons
2070 paper, Q72: explanation →A radioactive material of half life 5 days has its initial mass of 1 kg. The amount decayed after 20 days will be.
Answer: 937.5 g
2069 paper, Q70: explanation →NPN transistors are most preferred over PNP transistors. It is because of
Answer: Electrons have high mobility than holes
2081 paper, Q37: explanation →If germanium is doped with donor impurity the donor atom should be
Answer: pentavalent
2081 paper, Q40: explanation →The truth table given below is for: [Table: A=0,B=0 gives Y=0; A=0,B=1 gives Y=0; A=1,B=0 gives Y=0; A=1,B=1 gives Y=1]
Answer: AND gate
2080 paper, Q49: explanation →NPN transistors are preferred to PNP transistors because they have
Answer: Electrons have high mobility than holes and hence high mobility of energy
2080 paper, Q50: explanation →In P-type semiconductor, the majority and minority charge carries are respectively
Answer: Holes and electrons
2079 paper, Q25: explanation →In the depletion layer of an unbiased p-n junction diode, there are
Answer: only fixed ions
2078 paper, Q75: explanation →NPN transistors are most preferred than that of PNP transistor. It is because of
Answer: high mobility of electrons than that of holes
2077 paper, Q75: explanation →To obtain p-type silicon semiconductor, pure silicon may be doped with
Answer: aluminum
2075 paper, Q50: explanation →In some substances charge can flow at ordinary temperature but not at very low temperature. These are
Answer: semiconductors
2074 paper, Q75: explanation →On increasing the reverse bias to a large value in a p-n junction diode, the current
Answer: suddenly increases
2073 paper, Q71: explanation →A common emitter transistor amplifier has a current gain of 50. If the load resistance is $4,k\Omega$ and the input resistance is $500,\Omega$, the voltage gain of the amplifier is
Answer: 400
2070 paper, Q73: explanation →Fire alarm (fire dram) works on the principle of
Answer: Bimetallic bar which becomes curved on heating.
2081 paper, Q22: explanation →Fire alarm work on the principle of
Answer: Bimetallic bar which become curve on heating
2080 paper, Q33: explanation →A metal sheet has a circular hole in it. When it is heated, diameter of the hole
Answer: increases
2079 paper, Q9: explanation →Two copper rods of equal length and unequal diameters are heated through the same range of temperature. Its increase in length will be
Answer: same in both rod
2078 paper, Q58: explanation →A metallic ball is immersed in alcohol. The coefficient of cubical expansion of metal is less than that of alcohol. When the system is heated weight of ball is
Answer: Increases
2077 paper, Q57: explanation →The material of least linear expansivity is
Answer: invar
2075 paper, Q32: explanation →A steel bridge has length 700 m; the temperature varies from 243 K to 131 K. The change in length is ($\alpha=11\times10^{-6}$/K)
Answer: 86.24 cm
2074 paper, Q56: explanation →A square plate of side 2 units is heated through $10^\circ$C. If the linear expansivity of the material is $x$, increase in the surface area of the plate is
Answer: 80 x
2072 paper, Q59: explanation →When a cylinder is heated, its length increases by $2%$, the area of its base will increase by:
Answer:
2071 paper, Q57: explanation →An iron ball is heated. The percentage increase will be largest in
Answer: volume
2070 paper, Q54: explanation →If radii of a solid and hollow sphere are same. Which can hold greater number of charges?
Answer: Both will hold equal charges
2080 paper, Q38: explanation →A parallel plate capacitor is charged and the battery is then disconnected. If the plates of capacitors are removed apart by means of insulating handles
Answer: The voltage across the plate increases
2079 paper, Q17: explanation →In order to increase the capacity of a parallel plate capacitor one should introduce between the plates a sheet of
Answer: mica
2078 paper, Q64: explanation →n equal capacitors are first connected in series and then in parallel. The ratio of maximum to minimum capacitance is
Answer: $n^2$
2077 paper, Q66: explanation →Two capacitors of capacitances $2\mu$F and $3\mu$F are connected in parallel. The ratio of charges on them will be
Answer: 2:3
2076 paper, Q40: explanation →$n$ equal capacitors are first connected in series and then in parallel. The ratio of maximum to minimum capacitance is
Answer: $n^2$
2075 paper, Q41: explanation →Three capacitors each of capacitance 3 $\mu$F are connected in series. The net capacitance is
Answer: 1 F
2073 paper, Q65: explanation →A spherical condenser of 1 Farad will have the dimension of
Answer: a sphere having radius of more than that of earth
2072 paper, Q68: explanation →The radius of Earth is 6400 km. The capacitance is:
Answer: 711 F
2071 paper, Q69: explanation →Three capacitors of $3\mu F$, $9\mu F$ and $18\mu F$ are connected first in series and then in parallel. The ratio of $C$ equivalent capacitance in two cases ($C_s/C_p$) will be
Answer: $1:15$
2070 paper, Q64: explanation →A strong argument for particle nature of cathode rays is that they
Answer: Get deflected by electric and magnetic field
2079 paper, Q21: explanation →When objects placed in a room are exposed to X-rays, they appear
Answer: Invisible
2079 paper, Q22: explanation →If an electron has initial velocity in a direction perpendicular to the direction of electric field, the path of an electron is
Answer: parabola
2078 paper, Q71: explanation →When electrons are accelerated by $50,\text{kV}$ and $0.4%$ of energy of cathode rays is converted into x-rays and heat is evolved at $600,\text{W}$. The current is
Answer: $0.012,\text{A}$
2078 paper, Q73: explanation →Electron accelerated from rest to a potential difference of 100 volt. Its final velocity will be
Answer: $6\times10^6$ m/s
2077 paper, Q72: explanation →The colour of the positive column in a gas discharge tube depends on
Answer: the gas in the tube
2075 paper, Q47: explanation →The positive rays are
Answer: ions
2074 paper, Q72: explanation →The ratio of specific charge of a proton to that of an alpha particle is
Answer: 2:1
2072 paper, Q71: explanation →Which property of electrons is used in an electron microscope?
Answer: wave nature
2071 paper, Q67: explanation →Hard X-rays as compared to soft X-rays have
Answer: Higher frequency
2070 paper, Q71: explanation →The work done to blow a soap bubble of radius R is W, then work done to increase radius from R to 3R is
Answer:
2081 paper, Q20: explanation →A boy carries a bucket of water in one hand and a piece of plastic in the other. If he transfers the plastic into the bucket where it floats, the boy feels
Answer: same load
2081 paper, Q21: explanation →If length of wire is doubled keeping the diameter constant, its Young's modulus will
Answer: remain same
2077 paper, Q55: explanation →The work done to blow a soap bubble of radius 'R' is W, then work done to increase the radius from R to 3R is
Answer:
2077 paper, Q56: explanation →If the length of a wire is doubled keeping the diameter constant, its Young's modulus will
Answer: remain same
2075 paper, Q30: explanation →Powder clings to the skin because of
Answer: adhesion
2074 paper, Q54: explanation →The terminal velocity of a small sized spherical body of radius $r$ falling vertically in a viscous liquid is given as one of the following proportionality with radius.
Answer: $r^{2}$
2072 paper, Q55: explanation →The Poisson's ratio of material can't be
Answer:
2071 paper, Q55: explanation →Two wires A and B of the same material have lengths in the ratio $1:2$ and diameters in the ratio $2:1$. If they are pulled by the same force, their increase in length will be in the ratio
Answer: $1:8$
2070 paper, Q55: explanation →Whenever the magnetic flux linked with a coil changes, there is emf induced in a circuit. The emf lasts
Answer: as long as the change in flux takes place
2081 paper, Q28: explanation →Induced emf produced across the axle is maximum when it moves
Answer: at the poles
2081 paper, Q38: explanation →An emf of 2 volt is produced in a coil when current changes at steady rate from 3 to 2 amperes in 1 milli-second. The value of self-inductance is
Answer: $2,mH$
2080 paper, Q41: explanation →The self-inductance of a coil is $5,\text{mH}$. If a current of $2,\text{A}$ is flown, what will be the magnetic flux through the coil?
Answer: weber
2078 paper, Q65: explanation →Whenever the magnetic flux linked with a coil changes, there is emf induced in the circuit. The emf lasts
Answer: so long as the change in flux takes place
2075 paper, Q45: explanation →The self-inductance of a coil is 10 mH. If a current of 2 A flows, the magnetic flux through the coil is
Answer: 0.02 Wb
2074 paper, Q71: explanation →The self-inductance of a straight wire is
Answer: zero
2073 paper, Q68: explanation →The ratio of induced emf in a coil having 50 turns and rotating with 50 Hz to that of induced emf in a coil having 100 turns and rotating with 150 Hz in the same magnetic field is
Answer: 1:6
2072 paper, Q69: explanation →The energy stored in a 50 mH inductor carrying a current of 4 A is
Answer: 0.4 J
2070 paper, Q67: explanation →In an LCR circuit, the inductive reactance at resonance frequency is $100,\Omega$ and resistance is $5,\Omega$. The quality factor of the circuit is
Answer: 20
2081 paper, Q29: explanation →A circuit contains a capacitor of 420 pF and inductance $L$. The value of $L$ to broadcast on radio 1020 kHz is
Answer: $5.8\times10^{-5}H$
2081 paper, Q31: explanation →In L-C-R circuit, potential difference between terminals of inductance is 60 volts, between terminals of condenser is 30 volts, and between terminals of resistance is 40 volts. The supply voltage will be equal to
Answer: 50 volts
2080 paper, Q42: explanation →A source of 34 V and 50 Hz is connected in series with coil of 17 mH and resistor. If potential difference across resistor is 10 V, the potential difference across the coil is
Answer: 32 V
2079 paper, Q20: explanation →In a non-resonant circuit what will be the nature of the circuit for frequencies higher than the resonant frequency?
Answer: inductive
2078 paper, Q68: explanation →In LCR circuit, the inductive reactance at resonance frequency is 100 $\Omega$ and resistance is 5 Ohm, the quality factor of the circuit is
Answer: 20
2077 paper, Q70: explanation →A circuit contains a capacitor of 420 pf and an inductance L. The value of 'L' to broadcast on Radio at 1020 KHz is
Answer: $5.8\times10^{6}H$
2077 paper, Q71: explanation →The alternating current in an LCR circuit is maximum when
Answer: $X_L=X_C$
2070 paper, Q68: explanation →When a capacitor is added in series in an LCR circuit, the impedance of the circuit
Answer: increases or decreases depending upon the frequency of a.c
2069 paper, Q66: explanation →The maximum value of static friction is called
Answer: Limiting friction
2080 paper, Q30: explanation →A projectile is broken into two pieces at the maximum height. Then its
Answer: kinetic energy increases
2079 paper, Q4: explanation →Jet plane is based on the conservation of
Answer: linear momentum
2079 paper, Q5: explanation →To avoid slipping while walking on ice one should take smaller steps because of the
Answer: smaller friction
2078 paper, Q54: explanation →A scooter of mass $120,\text{kg}$ is moving with a uniform velocity of $108,\text{km/hr}$. The force required to stop the velocity in $10$ s is
Answer: $360,\text{N}$
2078 paper, Q55: explanation →The 'net force acting on a body is zero' then the wrong statement is
Answer: acceleration is not zero
2077 paper, Q54: explanation →A force of $5$ N acts on a body of weight $10$ N. The acceleration of the body is
Answer: $5$ m/s$^2$
2075 paper, Q27: explanation →Which of the following friction is maximum?
Answer: static
2073 paper, Q55: explanation →$\mu_s$ and $\mu_k$ are coefficient of static and kinetic frictions between two bodies. Then
Answer: $\mu_s\geq\mu_k$
2071 paper, Q53: explanation →A girl is sitting in a boat which is floating in Fewa Lake. If she drinks water from the lake, the level of water in the lake will be
Answer: Remain unchanged
2080 paper, Q32: explanation →Which of the following possesses highest viscosity?
Answer: honey
2079 paper, Q6: explanation →Up thrust depends upon
Answer: volume of liquid displaced
2078 paper, Q57: explanation →The surface energy of a drop of water of radius 'r' is proportional to
Answer: $r^2$
2076 paper, Q29: explanation →A body of volume 36 cc floats with 3/4 of its volume submerged in water. The density of body is
Answer: 0.75 g/cc
2076 paper, Q30: explanation →A rain drop of radius $0.3$ mm has terminal velocity $1$ m/s in air. The viscosity of air is $18\times10^{-5}$ poise, then viscous force is
Answer: $1.01\times10^{-7}$ N
2075 paper, Q31: explanation →Viscosity is the inherent property of liquids and gases and is more closely related to
Answer: transfer of momentum
2074 paper, Q55: explanation →A weightless rubber balloon has 100 g of water in it. Its weight in water will be
Answer: zero
2073 paper, Q57: explanation →Water flows through a tube of non-uniform cross section. If the radius at the entrance and exit is $3:2$, the ratio of velocity of liquid entering and leaving the tube is
Answer: $4:9$
2070 paper, Q56: explanation →The mean free path of a gas varies with pressure as
Answer: $p^{-1}$
2079 paper, Q10: explanation →The mean free path of a gas varies with pressure as
Answer: $P^{-1}$
2078 paper, Q59: explanation →The average kinetic energy per degree of freedom per molecule of an ideal gas is
Answer: $\frac12KT$
2077 paper, Q59: explanation →A glass vessel contains air at $27^\circ$C. The temperature to which it must be heated so that one-fourth of air is expelled from it at constant pressure is
Answer: $127^\circ$C
2075 paper, Q33: explanation →Which of the following gases possess maximum rms speed at a given temperature?
Answer: $H_2$
2073 paper, Q59: explanation →At what temperature the rms velocity of a hydrogen molecule will be equal to that of oxygen at $47^\circ C$?
Answer: 20 K
2072 paper, Q57: explanation →The mean free path of a gas varies with absolute temperature $(T)$ as
Answer:
2071 paper, Q59: explanation →The root mean square speed of hydrogen molecule at STP is 2 km per second. The rms speed of oxygen molecule at $810^0C$ is
Answer: $1,km,s^{-1}$
2069 paper, Q55: explanation →The study of photoelectric effect is useful in understanding
Answer: quantization on energy
2081 paper, Q33: explanation →The kinetic energy carried by emitted electron depends on
Answer: frequency
2081 paper, Q34: explanation →The Planck's constant can be experimentally determined by
Answer: photo-electric experiment
2078 paper, Q72: explanation →The kinetic energy carried by emitted electron depends on
Answer: Frequency
2075 paper, Q48: explanation →The wavelength of a photon is $4000\ \text{\AA}$. Its energy will be
Answer: 3.09 eV
2074 paper, Q73: explanation →The photoelectric effect is based on the law of conservation of
Answer: energy
2073 paper, Q69: explanation →If work function of a metal is 3.3 eV, the threshold frequency in photoelectric effect will be
Answer: $8\times10^{14}$ Hz
2069 paper, Q69: explanation →The variations of intensity with wavelength at different temperatures as shown in the figure will be [Figure: three black-body curves T1, T2, T3 with peaks at increasing wavelength in the order T1, T3, T2]
Answer: $T_1>T_3>T_2$
2079 paper, Q13: explanation →Two spheres of same material have radii in the ratio 3:2. The heat radiated by them at the same temperature will be
Answer: 9:4
2077 paper, Q60: explanation →A black body is at a temperature $727^\circ$C. It emits energy at the rate which is proportional to
Answer: $(1000)^4$
2076 paper, Q32: explanation →A cylinder of $0.6$ m long and $6$ mm radius is rated at $1.5$ kW. The temperature of the filament if Stefan's constant is $6\times10^{-8}\ \mathrm{W,m^{-2}K^{-4}}$ is
Answer: K
2075 paper, Q35: explanation →A black body radiates heat energy at the rate of $2\times10^{5}\ \mathrm{Js^{-1}m^{-2}}$ at a temperature of $127^\circ$C. The temperature of the black body at which the rate of heat radiation is $32\times10^{5}\ \mathrm{Js^{-1}m^{-2}}$ is
Answer: $527^\circ$C
2072 paper, Q60: explanation →Bolometer measures the
Answer: heat radiation
2069 paper, Q56: explanation →A sound wave has frequency 500 Hz and velocity 360 m/s. What is the distance between 2 particles having phase difference $60^0$?
Answer: 12 cm
2077 paper, Q64: explanation →The equation of a wave travelling in a string is given by $y=3\cos\pi(100t-x)$, where x and y are in cm and t is in second. Its wavelength is
Answer: 2 cm
2076 paper, Q44: explanation →A sound wave has frequency $500$ Hz and velocity $360$ m/s. What is the distance between 2 particles having phase difference $60^\circ$?
Answer: cm
2075 paper, Q39: explanation →In a longitudinal wave the displacement of the particles of the medium is
Answer: parallel or anti-parallel to the wave velocity
2074 paper, Q62: explanation →The equation of sound wave is $y=0.0015\sin(62.4x+316t)$. The wave length of sound wave is
Answer: 0.1 unit
2073 paper, Q72: explanation →A displacement wave is represented by $y=0.25\sin(500t-0.0025x)$, where $y$, $t$ and $x$ are in cm, second and meter respectively. The wavelength of the wave is
Answer: m
2070 paper, Q75: explanation →The slope of kinetic energy versus position gives the rate of
Answer: momentum
2081 paper, Q19: explanation →An atomic power station at Gujrat has a generating capacity of 200 MW. What will be the energy released in a day by the station?
Answer: $1.73\times10^{13}$ J
2081 paper, Q39: explanation →The graph of kinetic energy (KE) of a body versus velocity (V) is represented as [Figure: four KE vs V graphs: (a) straight line through origin, (b) concave-down curve, (c) upward-curving parabola from origin, (d) horizontal line]
Answer: (c)
2079 paper, Q7: explanation →Two masses 1 g and 4 g are moving with equal K.E. The ratio of their momentum is
Answer: 1:2
2076 paper, Q27: explanation →A force $F=(2\hat i+3\hat j-4\hat k)$ N acts on a body. In 5 seconds the force displaces the body through a displacement $s=(3\hat i+2\hat j-2\hat k)$ m. The power (in watt) of the force is
Answer: 4
2072 paper, Q51: explanation →Latent heat of substance is zero at
Answer: critical temperature
2081 paper, Q25: explanation →The boiling point of water inside the pressure cooker is
Answer: $120^\circ C$
2078 paper, Q60: explanation →Latent heat of a substance is zero at
Answer: critical temperature
2077 paper, Q58: explanation →50 g of ice at $-6^\circ$C is dropped into water at $0^\circ$C. How many grams of water freeze? Specific heat capacity of ice $=2000,J,kg^{-1}C^{-1}$.
Answer: 1.785 g
2070 paper, Q58: explanation →A bullet gets heated if stopped by a target. If its velocity is doubled the rise in temperature of the bullet will be
Answer: 4 times
2069 paper, Q75: explanation →Two fixed charges $q$ and $4q$ are $r$ distant apart. What will be the position of a third charge so that the system will be in equilibrium?
Answer: $2r/3$ from $4q$
2081 paper, Q26: explanation →Two fixed charges q and 4q are at r distance apart. What will be the position of a third charge to be placed so that the system will be in equilibrium?
Answer: 2r/3 from 4q
2077 paper, Q65: explanation →A body has 1 C of negative charge. How many excess electrons does it have compared to its neutral state?
Answer: $6.25\times10^{18}$
2074 paper, Q66: explanation →An isolated conducting sphere is given a positive charge. Its mass
Answer: decreases
2073 paper, Q64: explanation →A system of three charges may be in equilibrium. If they are placed
Answer: On a straight line
2071 paper, Q68: explanation →At a point on the axis of an electric dipole
Answer: Neither V nor E is zero.
2081 paper, Q30: explanation →The electric field intensity at the surface of a charged conductor is
Answer: directed normally to the surface
2078 paper, Q67: explanation →The torque on an electric dipole of moment $\vec p$ placed in an electric field $\vec E$ is proportional to
Answer: $P\cdot E$
2074 paper, Q68: explanation →Two charges of $2,\mu C$ and $4,\mu C$ are 1m apart. The electric field intensity is zero at a point between the charges. This point is approximately at a distance.
Answer: 41 cm from $2,\mu C$ charge
2069 paper, Q62: explanation →An electron in a field of $1,NC^{-1}$ will have an approximate acceleration.
Answer: $1.7\times10^{11},ms^{-2}$
2069 paper, Q74: explanation →During 5-12 September 2023, temperature at noon is recorded the same at the base camp of Mount Everest. A climber feels hottest when the relative humidity is
Answer: 99%
2080 paper, Q34: explanation →Liquids boils when its vapor pressure is
Answer: Equal to total pressure on surface
2076 paper, Q34: explanation →The temperature of a substance increases by $270^\circ$C. This increase is equal to
Answer: 270 K
2073 paper, Q58: explanation →In a pressure cooker food is cooked usually at a pressure
Answer: Two atmosphere
2071 paper, Q58: explanation →A temperature of $14^0F$ is equivalent to
Answer: 263 K
2069 paper, Q57: explanation →What is nuclear 'holocaust'?
Answer: After math of a nuclear explosion
2080 paper, Q46: explanation →When boron ${}_5B^{10}$ is bombarded by neutron, alpha particles are emitted. The resulting nucleus has the mass number
Answer: 7
2079 paper, Q24: explanation →The difference between ${}{92}U^{235}$ and ${}{92}U^{238}$ atom is
Answer: ${}_{92}U^{238}$ contains 3 more neutrons
2078 paper, Q74: explanation →A nuclear reactor has a power of $16$ kW. If the energy per fission is $200$ MeV then number of fission per second is
Answer: $5\times10^{14}$
2075 paper, Q49: explanation →The approximate radius of aluminum nucleus (Al) is
Answer: 4.5 Fermi
2072 paper, Q73: explanation →A mass $m$ is attached with two identical springs as shown in the figure and has frequency $f$. If one of the springs is removed, then the frequency will be
Answer: $f/\sqrt{2}$
2079 paper, Q8: explanation →A simple pendulum set into vibration comes to rest after some time because of
Answer: friction of air
2074 paper, Q53: explanation →Two simple harmonic waves are represented respectively by $y_1=A_1\sin\omega t$ and $y_2=A_2\cos\omega t$. The phase difference between the two waves is
Answer: $\pi/2$
2072 paper, Q52: explanation →The acceleration of a particle in SHM is
Answer: Maximum at extreme position
2070 paper, Q53: explanation →The duration in which the displacement becomes half the amplitude in the case of a simple harmonic motion if its period is 12 second, is
Answer: 1 sec
2069 paper, Q51: explanation →Light of wavelength 550 nm falls normally on a slit of width $22\times10^{-7}$ m. The angular position of second minima from central maxima will be
Answer: $30^\circ$
2079 paper, Q12: explanation →Light of wavelength 550 nm falls normally on a slit of width $22\times10^{-5}m$, the angular position of second minima from central maxima will be
Answer: $30^0$
2077 paper, Q61: explanation →Light of wavelength $550$ nm falls normally on a slit of width $22\times10^{-7}$ m. The angular position of the second minima from the central maxima will be
Answer: $30^\circ$
2075 paper, Q36: explanation →The bending of sound waves through the corners of the obstacle is called
Answer: diffraction
2071 paper, Q61: explanation →A diffraction grating has 5000 lines per cm. The maximum order visible with the radiation of wavelength 600nm in diffraction experiment is
Answer: 3
2069 paper, Q60: explanation →Sweetness of sound depends upon its
Answer: periodicity and regularity
2079 paper, Q16: explanation →A source of frequency 150 Hz is moving in a direction of a person with a velocity of 110 m/s. The frequency heard by the person will be (Velocity of sound = 330 m/s).
Answer: 225 Hz
2076 paper, Q45: explanation →While standing still, an observer measures the frequency of a tuning fork to be 524 Hz. What frequency does he measure as he approaches the fork at 5 m/s? (speed of sound 340 m/s)
Answer: 532 Hz
2074 paper, Q61: explanation →A car at rest is playing 'HORN'. If it starts moving towards you, the pitch heard would be
Answer: higher
2073 paper, Q74: explanation →Two vehicles are approaching each other with a speed of 10 m/s each. If A emits a note of 1000 vibrations, what will be the frequency of the note as heard by a person sitting in B if the velocity of sound is 330 m/s?
Answer: 1062.5 Hz
2072 paper, Q64: explanation →In Young's double slit experiment the distance of the tenth bright fringe from the centre of the interference pattern on either side is $3.44,\text{cm}$. If the screen is at $2,\text{m}$ and the wavelength is $589,\text{nm}$, the slit separation is
Answer: $0.34,\text{mm}$
2078 paper, Q56: explanation →In young's double slit experiment of interference, the distance between the slits is gradually increased. The width of the fringe system
Answer: decreases
2076 paper, Q37: explanation →When two waves overlap the result is a large disturbance means
Answer: The interference is constructive.
2074 paper, Q60: explanation →By using white light in double slit interference experiment the central fringe is white. What color of fringe can be seen nearest to the central fringe?
Answer: violet
2072 paper, Q62: explanation →Two waves of the same wavelength and amplitude interfere to give a minimum when their phase difference is
Answer:
2070 paper, Q70: explanation →In stationary wave
Answer: strain is max. at nodes
2076 paper, Q46: explanation →An open pipe and a closed pipe resonate to the same tuning fork. The ratio of their lengths is
Answer: 2:1
2072 paper, Q65: explanation →When a tuning fork is vibrated its prongs have a phase difference of:
Answer:
2071 paper, Q62: explanation →A tube closed at one end has a length 1 meter. The air column in the pipe can resonate for sound of frequency ($v=320,ms^{-1}$)
Answer: 80 Hz
2070 paper, Q74: explanation →An open organ pipe can produce
Answer: both odd and even harmonics
2069 paper, Q63: explanation →The efficiency of a heat engine will be $100%$ if the temperature of the sink is
Answer: K
2075 paper, Q34: explanation →The efficiency of a steam engine is of the order of
Answer: 10%
2074 paper, Q58: explanation →Dimension of the change in entropy is
Answer: $[M^1L^2T^{-2}K^{-1}]$
2072 paper, Q58: explanation →The efficiency of Carnot engine working between steam and ice point is:
Answer:
2071 paper, Q60: explanation →The temperature of source and sink of a Carnot engine are 400 K and 300 K respectively. What is its efficiency?
Answer: 25%
2070 paper, Q60: explanation →A vector is multiplied by 2, then
Answer: neither direction reverses nor unit changes but magnitude is doubled
2081 paper, Q17: explanation →A vector is multiplied by -2, then
Answer: direction reverses and magnitude is doubled
2079 paper, Q2: explanation →If the magnitudes of two vectors are $3$ and $4$ and the value of their scalar product is $6$, the angle between them is
Answer: $60^\circ$
2078 paper, Q52: explanation →A man walks 8 m forwards East and 6 m towards North. The magnitude of displacement is
Answer: $\sqrt{8^2+6^2}$ m
2073 paper, Q53: explanation →The magnetic field of Earth is due to
Answer: Motion and distribution of materials in and around the Earth
2080 paper, Q43: explanation →The material used for permanent magnet has
Answer: high retentivity, high coercivity
2078 paper, Q69: explanation →The property of retentivity of material is useful in construction of
Answer: permanent magnet
2075 paper, Q46: explanation →Magnetism of a magnet
Answer: becomes practically zero at Curie temperature
2074 paper, Q70: explanation →For a convex mirror, the variation of $u$ and $v$ is given by [Figure: four V vs u graphs: (a) rising curve that flattens, (b) straight line up, (c) falling hyperbola, (d) straight line down]
Answer: (a)
2079 paper, Q15: explanation →The field of view is maximum for
Answer: convex mirror
2073 paper, Q61: explanation →The image of an object placed at the focus of convex mirror is at a distance
Answer: $f/2$
2071 paper, Q63: explanation →The image of an object placed at the focus of a concave mirror is at
Answer: Infinity
2070 paper, Q59: explanation →The refractive index is 1.414 and refracting angle is $60^0$, then minimum deviation of light will be
Answer: $30^0$
2077 paper, Q63: explanation →The refracting angle of a prism of refractive index $\sqrt2$ is $60^\circ$. The minimum deviation from it is
Answer: $30^\circ$
2076 paper, Q36: explanation →When a light beam is incident on a prism, it causes
Answer: dispersion and deviation both
2074 paper, Q64: explanation →When two prisms are combined it gives
Answer: Dispersion or deviation
2071 paper, Q66: explanation →A perfect gas ($\gamma=1.5$) is compressed to one fourth of the original volume. If initial pressure of the gas is 1 atmosphere and the compression be adiabatic, then final pressure will be
Answer: 8 atm
2076 paper, Q31: explanation →The internal energy of a perfect gas does not change during
Answer: isothermal process
2074 paper, Q57: explanation →A gas does maximum work when it expands
Answer: isobarically
2074 paper, Q59: explanation →The thermodynamic process in which the pressure of the system remains constant is called
Answer: isobaric
2070 paper, Q57: explanation →Sound travels in rocks in the form of
Answer: Both longitudinal and transverse elastic waves
2080 paper, Q37: explanation →A wave is reflected from a rigid support. The change of phase on reflection will be
Answer:
2073 paper, Q73: explanation →Velocity of sound in a gas is $330,ms^{-1}$ at STP. Its value at 300k will nearly be
Answer: $360,ms^{-1}$
2069 paper, Q72: explanation →To draw maximum current from a combination of cells, the cells be grouped as
Answer: mixed
2080 paper, Q39: explanation →Wheatstone bridge is used to measure
Answer: resistance
2074 paper, Q69: explanation →A galvanometer (0-100) mA of resistance $1\ \Omega$ is to be converted to an ammeter in the range 0-1 A. We have to use a shunt
Answer: $0.111\ \Omega$
2072 paper, Q70: explanation →The force of gravitational attraction on a body is
Answer: Minimum at the equator
2076 paper, Q28: explanation →The depth from the surface of the earth at which the acceleration due to gravity becomes half of that on the earth's surface is
Answer: $R/2$
2075 paper, Q28: explanation →If the speed of rotation of earth increases, the weight of the body on earth's surface becomes
Answer: smaller
2073 paper, Q56: explanation →2% of light emitted by a source of luminous intensity 500 cd falls normally on a circular disc of radius 10 cm, calculate the average illumination of surface.
Answer: 4000 lun
2076 paper, Q38: explanation →The illuminance at a distance of 2 m from a 100 candela lamp is
Answer: 25 lux
2074 paper, Q63: explanation →A hollow metal sphere of radius 10 cm is charged such that the potential at its surface is 80 V. The potential at the center of sphere is
Answer: 80V
2076 paper, Q39: explanation →In bringing an electron towards another electron, the electrostatic potential energy of the system
Answer: increases
2075 paper, Q40: explanation →Spokes in a bicycle wheel are used to
Answer: increase moment of inertia
2075 paper, Q29: explanation →A constant torque acting on a uniform circular wheel changes its angular momentum from $L_0$ to $4L_0$ in 4 seconds. The magnitude of this torque is
Answer: $\left(\frac{3}{4}\right)L_0$
2072 paper, Q56: explanation →Sky seen from earth appears blue because of
Answer: scattering of lights
2073 paper, Q62: explanation →If sky is seen from moon's surface, it will appear
Answer: Black
2071 paper, Q64: explanation →At neutral temperature the thermoelectric power is
Answer: Zero
2081 paper, Q32: explanation →A body of mass 1 kg is rotated in a horizontal circle of radius 50 cm. If F and v represent the centripetal force and the constant speed respectively, which one of the following expressions may be correct?
Answer: $v=\sqrt{\frac F2}$
2069 paper, Q54: explanation →India has become the first country to successfully land a spacecraft Chandrayaan-3 near the south pole of the Moon. Its rover has confirmed the presence of
Answer: Oxygen and Sulphur
2080 paper, Q31: explanation →Oppenheimer is a 2023 biographical drama film written and directed by Christopher Nolan and starring Cillian Murphy as J. Robert Oppenheimer a physicist. His scientific contribution is
Answer: Design of Atom Bomb
2080 paper, Q47: explanation →The depth of water at which air-bubble of radius $0.4$ mm may remain in equilibrium (surface tension of water $=72\times10^{-3},N/m$, $g=9.8,m/s^2$) is given by
Answer: cm
2071 paper, Q56: explanation →