Physics MCQ

Question : The magnetic field at the centre of a circular loop of radius R carrying current I is
μ₀I/(4πR)
μ₀I/(2R)
μ₀I/(2πR)
μ₀I/(4R)
Correct Answer : μ₀I/(2R)

Question : A particle is projected vertically upward with a speed of 20 m/s. Taking g = 10 m/s², the maximum height reached by the particle is
10 m
20 m
30 m
40 m
Correct Answer : 20 m

Question : A car accelerates uniformly from 10 m/s to 20 m/s in 5 s. Its acceleration is
1 m/s²
2 m/s²
3 m/s²
4 m/s²
Correct Answer : 2 m/s²

Question : The SI unit of impulse is
N
N s
J s
W
Correct Answer : N s

Question : A force of 10 N acts on a body and displaces it by 5 m in the direction of the force. The work done is
2 J
15 J
50 J
100 J
Correct Answer : 50 J

Question : A stone of mass 2 kg is moving with a velocity of 4 m/s. Its momentum is
2 kg m/s
4 kg m/s
8 kg m/s
16 kg m/s
Correct Answer : 8 kg m/s

Question : A body of mass 5 kg is lifted vertically through a height of 4 m. Taking g = 10 m/s², the increase in its potential energy is
20 J
50 J
100 J
200 J
Correct Answer : 200 J

Question : The acceleration due to gravity at a height equal to the radius of Earth above its surface is
g
g/2
g/4
g/9
Correct Answer : g/4

Question : Two bodies of masses 2 kg and 8 kg have the same kinetic energy. The ratio of their momenta is
1 : 2
1 : 4
1 : 8
2 : 1
Correct Answer : 1 : 2

Question : A satellite is moving in a circular orbit around Earth. The work done by gravitational force during one complete revolution is
Positive
Negative
Zero
Infinite
Correct Answer : Zero

Question : The moment of inertia of a uniform disc about an axis passing through its centre and perpendicular to its plane is
MR²
MR²/2
MR²/4
2MR²
Correct Answer : MR²/2

Question : A simple pendulum has a time period T on Earth. If its length is increased four times, its new time period will be
T/2
T
2T
4T
Correct Answer : 2T

Question : In simple harmonic motion, the acceleration of the particle is maximum at
Mean position
Extreme position
Halfway between mean and extreme position
Every position equally
Correct Answer : Extreme position

Question : A wave has frequency 500 Hz and wavelength 0.6 m. Its speed is
30 m/s
300 m/s
600 m/s
833 m/s
Correct Answer : 300 m/s

Question : The pressure exerted by an ideal gas on the walls of its container is primarily due to
Gravitational attraction between molecules
Collisions of molecules with the walls
Electrostatic attraction between molecules
Chemical reactions between molecules
Correct Answer : Collisions of molecules with the walls

Question : During an isobaric expansion of an ideal gas, the pressure remains
Zero
Constant
Increasing continuously
Decreasing continuously
Correct Answer : Constant

Question : One mole of an ideal gas at temperature T has average translational kinetic energy per molecule equal to
kT
3kT/2
2kT
3kT
Correct Answer : 3kT/2

Question : A Carnot engine operates between 500 K and 300 K. Its maximum possible efficiency is
20%
30%
40%
60%
Correct Answer : 40%

Question : The electric potential at a point is 10 V. The work required to bring a charge of 2 C from infinity to that point is
5 J
10 J
20 J
40 J
Correct Answer : 20 J

Question : Two point charges exert a force F on each other when separated by distance r. If their separation is doubled, the new force becomes
F/2
F/4
2F
4F
Correct Answer : F/4

Question : A capacitor is charged to a potential difference V and then disconnected from the battery. If its capacitance is doubled, its new potential difference becomes
2V
V
V/2
V/4
Correct Answer : V/2

Question : Three resistors of 2 Ω, 3 Ω and 5 Ω are connected in series. Their equivalent resistance is
1 Ω
5 Ω
8 Ω
10 Ω
Correct Answer : 10 Ω

Question : A 12 V battery is connected across a 6 Ω resistor. The current through the resistor is
0.5 A
1 A
2 A
6 A
Correct Answer : 2 A

Question : A charged particle enters a uniform magnetic field with its velocity parallel to the field. The magnetic force on the particle is
Maximum
Zero
qvB
qB/v
Correct Answer : Zero

Question : A current-carrying conductor is placed perpendicular to a uniform magnetic field. The magnetic force on it is
Zero
Minimum but non-zero
Maximum
Independent of current
Correct Answer : Maximum

Question : The magnetic field inside a long ideal solenoid is directly proportional to
1/n
Current through the solenoid
Square of current
Radius of the solenoid only
Correct Answer : Current through the solenoid

Question : A coil of 100 turns experiences a change in magnetic flux of 0.02 Wb in 0.1 s. The magnitude of induced emf is
2 V
10 V
20 V
200 V
Correct Answer : 20 V

Question : In an AC circuit, the RMS value of current is 5 A. The peak value of current is
2.5 A
5 A
5√2 A
10 A
Correct Answer : 5√2 A

Question : An electromagnetic wave has a frequency of 6 × 10¹⁴ Hz. Its wavelength in vacuum is approximately
5 × 10⁻⁷ m
5 × 10⁻⁶ m
5 × 10⁻⁸ m
5 × 10⁷ m
Correct Answer : 5 × 10⁻⁷ m

Question : A ray of light passes from air into glass. Which quantity remains unchanged?
Speed
Wavelength
Frequency
Direction in all cases
Correct Answer : Frequency

Question : An object is placed at 2F in front of a convex lens. The image formed is
Virtual and magnified
Real, inverted and same size
Real and diminished
Virtual and diminished
Correct Answer : Real, inverted and same size

Question : The refractive index of a medium is 1.5. If the speed of light in vacuum is 3 × 10⁸ m/s, the speed of light in the medium is
1 × 10⁸ m/s
2 × 10⁸ m/s
3 × 10⁸ m/s
4.5 × 10⁸ m/s
Correct Answer : 2 × 10⁸ m/s

Question : In Young's double-slit experiment, if the slit separation is increased while all other parameters remain unchanged, the fringe width
Increases
Decreases
Remains unchanged
Becomes zero
Correct Answer : Decreases

Question : The threshold frequency of a metal is ν₀. If incident light has frequency 2ν₀, the maximum kinetic energy of emitted photoelectrons is
0
hν₀
2hν₀
hν₀/2
Correct Answer : hν₀

Question : The energy of a photon having wavelength λ is
hcλ
hc/λ
hλ/c
λ/hc
Correct Answer : hc/λ

Question : In Rutherford's alpha-particle scattering experiment, most alpha particles passed through the foil undeflected because
Atoms are electrically neutral
Nuclei are negatively charged
Most of the atom is empty space
Alpha particles have no charge
Correct Answer : Most of the atom is empty space

Question : The half-life of a radioactive substance is 5 years. After 15 years, the fraction of the original substance remaining is
1/2
1/4
1/8
1/16
Correct Answer : 1/8

Question : A semiconductor diode is generally used as a rectifier because it
Has very high resistance in both directions
Conducts mainly in one direction
Produces alternating current
Has zero resistance in both directions
Correct Answer : Conducts mainly in one direction

Question : In an n-type semiconductor, the majority charge carriers are
Holes
Protons
Electrons
Neutrons
Correct Answer : Electrons

Question : A transistor has current gain β = 100. If the base current is 20 μA, the collector current is
0.2 mA
1 mA
2 mA
20 mA
Correct Answer : 2 mA

Question : The de Broglie wavelength of an electron accelerated through a potential difference V is proportional to
V
√V
1/V
1/√V
Correct Answer : 1/√V

Question : The mass defect of a nucleus is directly related to its
Atomic number only
Binding energy
Chemical reactivity
Half-life only
Correct Answer : Binding energy

Question : A particle has momentum p and kinetic energy K. For a non-relativistic particle, the relation between them is
K = p/m
K = p²/(2m)
K = 2mp²
K = p²m
Correct Answer : K = p²/(2m)

Question : A wire has resistance 10 Ω at 20°C. If its temperature coefficient of resistance is positive, its resistance at 100°C will be
Definitely less than 10 Ω
Definitely equal to 10 Ω
Greater than 10 Ω
Zero
Correct Answer : Greater than 10 Ω

Question : A battery of emf E and internal resistance r supplies current I to an external resistance R. The terminal voltage of the battery is
E + Ir
E - Ir
Ir - E
E/R
Correct Answer : E - Ir

Question : A charged capacitor is connected across a resistor. During discharge, the charge on the capacitor
Increases linearly
Remains constant
Decreases exponentially
Decreases linearly to zero
Correct Answer : Decreases exponentially

Question : A block slides down a frictionless inclined plane of angle 30°. Its acceleration is
g
g/2
g/√2
√3g/2
Correct Answer : g/2

Question : A projectile has maximum horizontal range R on Earth. If its initial speed is doubled, its maximum possible range becomes
R
2R
4R
R/2
Correct Answer : 4R

Question : A body is in equilibrium under the action of three concurrent forces. If two forces are perpendicular and have magnitudes 3 N and 4 N, the magnitude of the third force is
1 N
5 N
7 N
12 N
Correct Answer : 5 N

Question : The escape velocity from a planet is 11.2 km/s. If the radius of the planet is doubled while its mass remains unchanged, the escape velocity becomes
22.4 km/s
11.2 km/s
7.92 km/s
5.6 km/s
Correct Answer : 7.92 km/s

Question : A uniform rod of mass M and length L is rotating about an axis through its centre and perpendicular to its length with angular velocity ω. Its rotational kinetic energy is
ML²ω²/2
ML²ω²/6
ML²ω²/24
ML²ω²/12
Correct Answer : ML²ω²/24

Question : A particle moves along a straight line with initial velocity 5 m/s and acceleration 2 m/s². Its velocity after 4 s is
7 m/s
9 m/s
13 m/s
15 m/s
Correct Answer : 13 m/s

Question : A stone is dropped from a height of 45 m. Taking g = 10 m/s², the time taken to reach the ground is
2 s
3 s
4 s
5 s
Correct Answer : 3 s

Question : Two vectors of magnitudes 3 and 4 units are perpendicular to each other. The magnitude of their resultant is
1 unit
5 units
7 units
12 units
Correct Answer : 5 units

Question : A 4 kg block is acted upon by a net force of 12 N. Its acceleration is
0.33 m/s²
3 m/s²
8 m/s²
48 m/s²
Correct Answer : 3 m/s²

Question : A body of mass 2 kg is moving with speed 6 m/s. Its linear momentum is
3 kg m/s
8 kg m/s
12 kg m/s
18 kg m/s
Correct Answer : 12 kg m/s

Question : A 1000 kg car moving at 10 m/s is brought to rest. The magnitude of its change in momentum is
1000 kg m/s
5000 kg m/s
10000 kg m/s
20000 kg m/s
Correct Answer : 10000 kg m/s

Question : A body is projected horizontally from the top of a 20 m high tower with speed 10 m/s. Taking g = 10 m/s², the horizontal distance travelled before hitting the ground is
10 m
20 m
30 m
40 m
Correct Answer : 20 m

Question : The gravitational potential energy of a body of mass m at a height h above Earth's surface, for h much smaller than Earth's radius, is approximately
mgh
mg/h
mh/g
gh/m
Correct Answer : mgh

Question : If the radius of a planet is half that of Earth and its mass is one-fourth that of Earth, the acceleration due to gravity on its surface is
g/2
g
2g
4g
Correct Answer : g

Question : A solid sphere and a hollow sphere of the same mass and radius roll down an inclined plane without slipping. Which reaches the bottom first?
Solid sphere
Hollow sphere
Both reach simultaneously
Cannot be determined
Correct Answer : Solid sphere

Question : A disc and a ring, having the same mass and radius, roll without slipping with the same speed. The ratio of their rotational kinetic energies is
1 : 1
1 : 2
2 : 1
1 : 4
Correct Answer : 1 : 2

Question : A spring is compressed by 0.1 m and has force constant 200 N/m. The elastic potential energy stored in it is
0.5 J
1 J
2 J
10 J
Correct Answer : 1 J

Question : A particle executes SHM with angular frequency 5 rad/s and amplitude 0.2 m. Its maximum speed is
0.04 m/s
0.2 m/s
1 m/s
2.5 m/s
Correct Answer : 1 m/s

Question : Two sound waves have frequencies 256 Hz and 260 Hz. The number of beats produced per second is
2
4
8
516
Correct Answer : 4

Question : A gas is compressed isothermally. The work done by the gas is
Always positive
Always zero
Negative
Infinite
Correct Answer : Negative

Question : For an ideal gas, the internal energy depends only on
Pressure
Volume
Temperature
Pressure and volume independently
Correct Answer : Temperature

Question : The rms speed of gas molecules is proportional to
T
√T
1/T
1/√T
Correct Answer : √T

Question : A heat engine absorbs 500 J of heat from a source and rejects 300 J to the sink. Its efficiency is
20%
30%
40%
60%
Correct Answer : 40%

Question : Two charges +q and -q are separated by a distance 2a. The electric field at the midpoint is directed
From +q towards -q
From -q towards +q
Perpendicular to the line joining the charges
Zero
Correct Answer : From +q towards -q

Question : A charge q is placed in an electric field E. The force acting on it is
q/E
E/q
qE
q + E
Correct Answer : qE

Question : An electric dipole placed in a uniform electric field experiences maximum torque when the angle between its dipole moment and the electric field is
0°
30°
60°
90°
Correct Answer : 90°

Question : A capacitor of capacitance 4 μF is charged to 100 V. The energy stored in it is
0.01 J
0.02 J
0.04 J
0.08 J
Correct Answer : 0.02 J

Question : If the length of a wire is doubled and its cross-sectional area is halved, its resistance becomes
R/4
R/2
2R
4R
Correct Answer : 4R

Question : In a balanced Wheatstone bridge, the resistance ratio P/Q is equal to
R/S
S/R
R + S
R - S
Correct Answer : R/S

Question : A charged particle moves perpendicular to a uniform magnetic field. If its speed is doubled, the radius of its circular path becomes
Half
Unchanged
Double
Four times
Correct Answer : Double

Question : A moving charge produces
Only an electric field
Only a magnetic field
Both electric and magnetic fields
Neither electric nor magnetic field
Correct Answer : Both electric and magnetic fields

Question : Lenz's law is a consequence of the law of conservation of
Charge
Mass
Energy
Momentum
Correct Answer : Energy

Question : An ideal transformer has 500 turns in its primary coil and 1000 turns in its secondary coil. If the primary voltage is 20 V, the secondary voltage is
5 V
10 V
40 V
100 V
Correct Answer : 40 V

Question : A convex lens has focal length 20 cm. Its power is
+2 D
+5 D
−2 D
−5 D
Correct Answer : +5 D

Question : An object is placed between the optical centre and focus of a convex lens. The image formed is
Real, inverted and diminished
Real, inverted and magnified
Virtual, erect and magnified
Virtual, erect and diminished
Correct Answer : Virtual, erect and magnified

Question : The slope of a velocity-time graph represents
Displacement
Acceleration
Momentum
Force
Correct Answer : Acceleration

Question : A particle moves in a circle of radius 2 m with constant speed 4 m/s. Its centripetal acceleration is
2 m/s²
4 m/s²
8 m/s²
16 m/s²
Correct Answer : 8 m/s²

Question : A projectile is thrown with a speed of 20 m/s at an angle of 45° to the horizontal. Taking g = 10 m/s², its time of flight is
1 s
2 s
2√2 s
4 s
Correct Answer : 2√2 s

Question : A force of 50 N acts on a body through a displacement of 4 m at an angle of 60° to the displacement. The work done is
50 J
100 J
150 J
200 J
Correct Answer : 100 J

Question : A 2 kg body moving at 5 m/s collides with a stationary 3 kg body. If they stick together, their common velocity is
1 m/s
2 m/s
3 m/s
5 m/s
Correct Answer : 2 m/s

Question : A body of mass 10 kg is moving with a speed of 2 m/s. If its speed becomes 6 m/s, the increase in kinetic energy is
80 J
120 J
160 J
180 J
Correct Answer : 160 J

Question : The coefficient of friction between a block and a horizontal surface is 0.4. If the mass of the block is 5 kg and g = 10 m/s², the limiting friction is
10 N
20 N
30 N
40 N
Correct Answer : 20 N

Question : A uniform circular disc has mass M and radius R. Its moment of inertia about a tangent perpendicular to its plane is
MR²/2
MR²
3MR²/2
2MR²
Correct Answer : 3MR²/2

Question : A wheel rotates with angular velocity 10 rad/s. If its radius is 0.5 m, the linear speed of a point on its rim is
2 m/s
5 m/s
10 m/s
20 m/s
Correct Answer : 5 m/s

Question : A planet has the same mass as Earth but twice its radius. The escape velocity from its surface compared with Earth is
Half
Same
Double
Four times
Correct Answer : Half

Question : The gravitational potential at a point on the surface of Earth is
Zero
GM/R
−GM/R
−GM/R²
Correct Answer : −GM/R

Question : A satellite in a circular orbit has kinetic energy K and potential energy U. The relation between K and U is
K = U
K = −U
K = −U/2
K = −2U
Correct Answer : K = −U/2

Question : A liquid flows through a horizontal pipe whose cross-sectional area decreases. According to Bernoulli's principle, the pressure in the narrower section is
Higher
Lower
Equal
Zero
Correct Answer : Lower

Question : Water flows through a pipe at a speed of 2 m/s. If the cross-sectional area is reduced to one-fourth, the speed becomes
0.5 m/s
2 m/s
4 m/s
8 m/s
Correct Answer : 8 m/s

Question : A liquid of density 1000 kg/m³ is flowing with speed 4 m/s. Its dynamic pressure is
2000 Pa
4000 Pa
8000 Pa
16000 Pa
Correct Answer : 8000 Pa

Question : A metal wire is heated. If its length increases by 0.1%, its linear strain is
0.001
0.01
0.1
1
Correct Answer : 0.001

Question : The Young's modulus of a material is defined as the ratio of
Stress to strain
Strain to stress
Force to displacement
Pressure to volume
Correct Answer : Stress to strain

Question : A gas expands freely into a vacuum. The work done by the gas is
Positive
Negative
Zero
Infinite
Correct Answer : Zero

Question : For a monatomic ideal gas, the ratio of specific heats γ is
4/3
5/3
7/5
3/2
Correct Answer : 5/3

Question : The mean free path of gas molecules increases when
Pressure increases
Pressure decreases
Temperature becomes zero
Molecular mass increases indefinitely
Correct Answer : Pressure decreases

Question : An electric field of 200 N/C acts on a charge of 5 μC. The force on the charge is
10⁻⁶ N
10⁻³ N
10⁻² N
10 N
Correct Answer : 10⁻³ N

Question : Two capacitors of 2 μF and 3 μF are connected in series. Their equivalent capacitance is
1.2 μF
2.5 μF
5 μF
6 μF
Correct Answer : 1.2 μF

Question : A charged capacitor is connected to a battery. If the dielectric constant of the material inserted between its plates is increased, the charge stored on the capacitor
Decreases
Remains unchanged
Increases
Becomes zero
Correct Answer : Increases

Question : The drift velocity of electrons in a metallic conductor is directly proportional to
Resistance
Electric field
Temperature only
Cross-sectional area only
Correct Answer : Electric field

Question : A wire carries a current of 3 A for 2 minutes. The total number of electrons passing through its cross-section is approximately
2.25 × 10²⁰
2.25 × 10²¹
3.75 × 10²⁰
3.75 × 10¹⁹
Correct Answer : 2.25 × 10²¹

Question : A charged particle moves in a uniform magnetic field with its velocity perpendicular to the field. Its kinetic energy
Increases continuously
Decreases continuously
Remains constant
Becomes zero
Correct Answer : Remains constant

Question : The magnetic moment of a current loop is maximum when the plane of the loop is
Parallel to the magnetic field
Perpendicular to the magnetic field
At 45° to the magnetic field
At 60° to the magnetic field
Correct Answer : Perpendicular to the magnetic field

Question : A coil has inductance 2 H and carries a current of 3 A. The energy stored in the magnetic field is
3 J
6 J
9 J
18 J
Correct Answer : 9 J

Question : In a series LCR circuit at resonance, the impedance is
Maximum
Minimum
Infinite
Zero in all cases
Correct Answer : Minimum

Question : A ray of light passes from water into air. Compared with its speed in water, its speed in air is
Smaller
Equal
Greater
Zero
Correct Answer : Greater

Question : A body starts from rest and moves with uniform acceleration of 4 m/s². The distance covered in the first 3 s is
6 m
12 m
18 m
24 m
Correct Answer : 18 m

Question : Two forces of 5 N and 12 N act on a body in opposite directions. The magnitude of their resultant is
7 N
13 N
17 N
60 N
Correct Answer : 7 N

Question : A person of mass 60 kg is standing in a lift accelerating upward at 2 m/s². Taking g = 10 m/s², the apparent weight of the person is
480 N
600 N
720 N
840 N
Correct Answer : 720 N

Question : A block is placed on a smooth inclined plane of angle 60° with the horizontal. Its acceleration down the plane is
g/2
g/√2
√3g/2
g
Correct Answer : √3g/2

Question : A 2 kg object is moving in a circular path of radius 5 m with speed 10 m/s. The centripetal force acting on it is
4 N
20 N
40 N
100 N
Correct Answer : 40 N

Question : A projectile is fired at an angle of 60° with the horizontal. The ratio of its maximum height to horizontal range is
1/2
√3/4
3/4
√3/2
Correct Answer : √3/4

Question : A 10 kg block is pulled by a force of 50 N on a horizontal surface. If the coefficient of kinetic friction is 0.2 and g = 10 m/s², its acceleration is
1 m/s²
2 m/s²
3 m/s²
5 m/s²
Correct Answer : 3 m/s²

Question : A body of mass 4 kg has momentum 20 kg m/s. Its kinetic energy is
25 J
40 J
50 J
100 J
Correct Answer : 50 J

Question : If the momentum of a particle is increased by 20%, its kinetic energy increases by approximately
20%
40%
44%
60%
Correct Answer : 44%

Question : A uniform rod of length L is suspended horizontally by two vertical strings attached at its ends. If a load is placed at a point one-fourth of the length from the left end, the ratio of tensions in the left and right strings is
1 : 3
3 : 1
1 : 1
2 : 3
Correct Answer : 3 : 1

Question : The moment of inertia of a thin ring about an axis passing through its centre and perpendicular to its plane is
MR²/2
MR²
2MR²
MR²/4
Correct Answer : MR²

Question : A torque of 10 N m acts on a wheel having moment of inertia 2 kg m². Its angular acceleration is
2 rad/s²
5 rad/s²
10 rad/s²
20 rad/s²
Correct Answer : 5 rad/s²

Question : The orbital velocity of a satellite close to the surface of Earth is related to the escape velocity ve by
vo = ve
vo = 2ve
vo = ve/2
vo = ve/√2
Correct Answer : vo = ve/√2

Question : If the temperature of an ideal gas is increased from 300 K to 600 K at constant volume, its pressure becomes
Half
Unchanged
Double
Four times
Correct Answer : Double

Question : A gas absorbs 500 J of heat and performs 200 J of work. The change in its internal energy is
−700 J
−300 J
300 J
700 J
Correct Answer : 300 J

Question : The ratio of the specific heats of a diatomic ideal gas is
4/3
5/3
7/5
9/7
Correct Answer : 7/5

Question : During an adiabatic expansion of an ideal gas, its temperature
Increases
Decreases
Remains constant
First increases and then decreases
Correct Answer : Decreases

Question : A Carnot engine operates between 600 K and 300 K. If it absorbs 1200 J of heat from the source, the work done per cycle is
300 J
600 J
900 J
1200 J
Correct Answer : 600 J

Question : A point charge produces an electric field of 100 N/C at a distance of 2 m. If the distance is increased to 4 m, the electric field becomes
12.5 N/C
25 N/C
50 N/C
200 N/C
Correct Answer : 25 N/C

Question : Two identical charges repel each other with force F. If the magnitude of each charge is doubled while their separation is also doubled, the new force is
F/4
F/2
F
2F
Correct Answer : F

Question : An electric dipole is placed in a uniform electric field with its dipole moment parallel to the field. The torque on it is
Maximum
Zero
pE
2pE
Correct Answer : Zero

Question : A capacitor of capacitance 5 μF is connected to a 20 V battery. The charge stored is
25 μC
50 μC
100 μC
200 μC
Correct Answer : 100 μC

Question : A resistor of resistance 10 Ω is connected to a 20 V source. The electrical power dissipated is
20 W
30 W
40 W
50 W
Correct Answer : 40 W

Question : Two resistors of 6 Ω and 3 Ω are connected in parallel. Their equivalent resistance is
1 Ω
2 Ω
3 Ω
9 Ω
Correct Answer : 2 Ω

Question : A cell of emf 2 V and internal resistance 0.5 Ω is connected to an external resistance of 1.5 Ω. The current in the circuit is
0.5 A
1 A
1.5 A
2 A
Correct Answer : 1 A

Question : A proton enters a uniform magnetic field perpendicular to the field. If its momentum is doubled, the radius of its circular path becomes
Half
Unchanged
Double
Four times
Correct Answer : Double

Question : A long straight conductor carries a current of 5 A. The magnetic field at a distance of 0.1 m from it is
1 × 10⁻⁶ T
1 × 10⁻⁵ T
1 × 10⁻⁴ T
1 × 10⁻³ T
Correct Answer : 1 × 10⁻⁵ T

Question : A conducting loop is moved toward a bar magnet. The induced current in the loop produces a magnetic field that
Attracts the magnet
Opposes the motion of the magnet
Always points upward
Is always zero
Correct Answer : Opposes the motion of the magnet

Question : An alternating voltage is given by V = 200 sin(100πt) volts. Its frequency is
25 Hz
50 Hz
100 Hz
200 Hz
Correct Answer : 50 Hz

Question : A convex mirror has focal length 20 cm. Its power in dioptres is
+2 D
+5 D
−2 D
−5 D
Correct Answer : −5 D

Question : A particle moves with a velocity of 10 m/s for 5 s and then with a velocity of 20 m/s for the next 5 s in the same direction. Its average velocity is
10 m/s
12 m/s
15 m/s
20 m/s
Correct Answer : 15 m/s

Question : A car moving at 20 m/s is brought to rest uniformly in 5 s. The distance travelled during this time is
25 m
50 m
75 m
100 m
Correct Answer : 50 m

Question : A projectile is launched with speed 20 m/s at an angle of 30° with the horizontal. Taking g = 10 m/s², its maximum height is
2.5 m
5 m
10 m
20 m
Correct Answer : 5 m

Question : A force of 20 N acts on a 5 kg body initially at rest. The kinetic energy acquired by the body after moving through 10 m is
100 J
200 J
400 J
500 J
Correct Answer : 200 J

Question : A 2 kg body moving at 10 m/s collides elastically head-on with a stationary 2 kg body. The velocity of the first body after collision is
0 m/s
5 m/s
10 m/s
20 m/s
Correct Answer : 0 m/s

Question : A body of mass 1 kg is attached to a spring of force constant 100 N/m. Its angular frequency of oscillation is
5 rad/s
10 rad/s
20 rad/s
100 rad/s
Correct Answer : 10 rad/s

Question : A simple pendulum has a time period of 2 s on Earth. On a planet where the acceleration due to gravity is four times that on Earth, its time period will be
0.5 s
1 s
2 s
4 s
Correct Answer : 1 s

Question : A particle in SHM has maximum displacement A. At the mean position, its potential energy is
Maximum
Minimum
Equal to its kinetic energy
Zero only when A = 0
Correct Answer : Minimum

Question : A wave travels with speed 340 m/s and has frequency 170 Hz. Its wavelength is
0.5 m
1 m
2 m
4 m
Correct Answer : 2 m

Question : Two tuning forks of frequencies 256 Hz and 260 Hz are sounded together. The time interval between two successive maxima of sound intensity is
0.125 s
0.25 s
0.5 s
4 s
Correct Answer : 0.25 s

Question : A liquid rises in a capillary tube due to
Viscosity
Surface tension
Elasticity
Atmospheric pressure alone
Correct Answer : Surface tension

Question : According to the equation of continuity for an incompressible fluid, the product of cross-sectional area and
Pressure is constant
Velocity is constant
Density is constant
Velocity is constant along a streamline
Correct Answer : Velocity is constant

Question : A metal wire has resistance R. If its length is reduced to half while its volume remains constant, its new resistance is
R/4
R/2
R
2R
Correct Answer : R/4

Question : The temperature of 2 moles of an ideal gas is increased from 300 K to 600 K at constant volume. The pressure becomes
Half
Unchanged
Double
Four times
Correct Answer : Double

Question : A gas undergoes an isochoric process. The work done by the gas is
Positive
Negative
Zero
Maximum
Correct Answer : Zero

Question : One mole of an ideal gas is heated at constant pressure. Which quantity increases?
Only pressure
Only volume
Both temperature and volume
Only internal energy
Correct Answer : Both temperature and volume

Question : A refrigerator transfers 600 J of heat from its cold chamber while consuming 200 J of work. Its coefficient of performance is
1
2
3
4
Correct Answer : 3

Question : A point charge q is placed at the centre of a cube. The electric flux through the entire cube is
q/(6ε₀)
q/(3ε₀)
q/ε₀
6q/ε₀
Correct Answer : q/ε₀

Question : Four identical charges are placed at the four corners of a square. The electric potential at the centre of the square is
Zero
Positive and finite
Negative and finite
Infinite
Correct Answer : Positive and finite

Question : A capacitor is charged to potential V and stores energy U. If its potential is doubled without changing its capacitance, the stored energy becomes
U/4
U/2
2U
4U
Correct Answer : 4U

Question : A 4 Ω resistor and a 12 Ω resistor are connected in parallel across a 24 V battery. The total current drawn from the battery is
2 A
4 A
6 A
8 A
Correct Answer : 8 A

Question : A wire carries a current of 2 A. If the number density of free electrons is increased while all other quantities remain unchanged, the drift velocity will
Increase
Decrease
Remain unchanged
Become infinite
Correct Answer : Decrease

Question : The magnetic field at the centre of a circular loop is B. If the current through the loop is doubled and its radius is halved, the magnetic field becomes
B
2B
4B
8B
Correct Answer : 4B

Question : An electron enters a uniform magnetic field with velocity perpendicular to the field. The magnetic force does no work because it is always
Parallel to velocity
Perpendicular to velocity
Opposite to velocity
Equal to electric force
Correct Answer : Perpendicular to velocity

Question : A coil of 200 turns experiences a change in magnetic flux of 5 × 10⁻³ Wb in 0.1 s. The induced emf is
1 V
5 V
10 V
20 V
Correct Answer : 10 V

Question : In an ideal transformer, the primary voltage is 220 V and the secondary voltage is 1100 V. If the primary has 100 turns, the number of secondary turns is
20
100
500
1000
Correct Answer : 500

Question : An AC current is represented by I = 10 sin(100πt) A. Its RMS value is
5 A
10 A
10√2 A
20 A
Correct Answer : 5√2 A

Question : In a series LCR circuit, resonance occurs when
XL > XC
XL < XC
XL = XC
R = 0
Correct Answer : XL = XC

Question : Light of wavelength 400 nm falls on a metal having threshold wavelength 500 nm. The emitted photoelectrons will have
Zero kinetic energy
Non-zero maximum kinetic energy
Infinite kinetic energy
No dependence on wavelength
Correct Answer : Non-zero maximum kinetic energy

Question : An electron and a proton have the same de Broglie wavelength. The ratio of their momenta is
1 : 1
1 : 1836
1836 : 1
√1836 : 1
Correct Answer : 1 : 1

Question : A particle moves with initial velocity 8 m/s and uniform acceleration −2 m/s². The time taken by it to come to rest is
2 s
4 s
6 s
8 s
Correct Answer : 4 s

Question : A velocity-time graph is a straight line parallel to the time axis. The particle is moving with
Uniform acceleration
Uniform velocity
Increasing acceleration
Zero velocity only
Correct Answer : Uniform velocity

Question : A ball is thrown vertically upward with speed 30 m/s. Taking g = 10 m/s², its velocity after 2 s is
10 m/s upward
10 m/s downward
20 m/s upward
20 m/s downward
Correct Answer : 10 m/s upward

Question : A force of 6 N acts on a body through a displacement of 3 m at an angle of 120° to the displacement. The work done is
−18 J
−9 J
9 J
18 J
Correct Answer : −9 J

Question : A machine performs 600 J of useful work while consuming 1000 J of energy. Its efficiency is
40%
50%
60%
80%
Correct Answer : 60%

Question : A 2 kg object is moving with speed 3 m/s. If a constant force does 16 J of work on it, its final speed is
4 m/s
5 m/s
6 m/s
7 m/s
Correct Answer : 5 m/s

Question : A man of mass 60 kg climbs a staircase of vertical height 5 m in 10 s. Taking g = 10 m/s², the average power developed is
150 W
300 W
600 W
3000 W
Correct Answer : 300 W

Question : A uniform rod of length 2 m and mass 3 kg is pivoted at one end. Its moment of inertia about the pivot is
2 kg m²
3 kg m²
4 kg m²
6 kg m²
Correct Answer : 4 kg m²

Question : A body rolls without slipping on a horizontal surface. The instantaneous velocity of the point of contact with the ground is
Maximum
Equal to the velocity of the centre
Zero
Twice the velocity of the centre
Correct Answer : Zero

Question : If the angular momentum of a rotating body remains constant and its moment of inertia becomes half, its angular velocity becomes
Half
Unchanged
Double
Four times
Correct Answer : Double

Question : The gravitational force between two masses is F. If one mass is doubled and the distance between them is also doubled, the new gravitational force is
F/4
F/2
F
2F
Correct Answer : F/2

Question : At a height equal to the radius of Earth above its surface, the gravitational potential due to Earth is
−GM/R
−GM/(2R)
−2GM/R
Zero
Correct Answer : −GM/(2R)

Question : A satellite revolves around Earth in a circular orbit of radius r with time period T. If its orbital radius becomes 8r, its new time period is
2T
4T
8T
16T
Correct Answer : 16T

Question : The pressure at a depth h below the free surface of a liquid of density ρ is
ρgh
ρg/h
h/(ρg)
ρ/hg
Correct Answer : ρgh

Question : A hydraulic lift has piston areas 0.01 m² and 1 m². If a force of 100 N is applied on the smaller piston, the force produced on the larger piston is
100 N
1000 N
5000 N
10000 N
Correct Answer : 10000 N

Question : Two identical droplets of a liquid coalesce to form one larger droplet. The ratio of the radius of the larger droplet to that of each smaller droplet is
2
2^(1/3)
√2
4
Correct Answer : 2^(1/3)

Question : A metal rod of length 1 m is heated through 100°C. If its coefficient of linear expansion is 2 × 10⁻⁵ °C⁻¹, its increase in length is
0.2 mm
2 mm
20 mm
0.02 mm
Correct Answer : 2 mm

Question : A gas is taken from state A to state B by two different thermodynamic paths. The change in internal energy is
Different for both paths
Same for both paths
Always zero
Dependent only on pressure
Correct Answer : Same for both paths

Question : An ideal gas undergoes a complete cyclic process. The net change in its internal energy is
Positive
Negative
Zero
Infinite
Correct Answer : Zero

Question : If the absolute temperature of an ideal gas is increased four times, its rms molecular speed becomes
One-fourth
Half
Double
Four times
Correct Answer : Double

Question : The electric field due to an infinite plane sheet of charge with surface charge density σ is
σ/ε₀
σ/(2ε₀)
2σ/ε₀
Zero
Correct Answer : σ/(2ε₀)

Question : A charge q is moved between two points on the same equipotential surface. The work done by the electrostatic field is
qV
q/V
Zero
Infinite
Correct Answer : Zero

Question : A charged capacitor is completely discharged through a resistor. The total energy initially stored in the capacitor is ultimately converted into
Mechanical energy
Chemical energy
Heat energy
Nuclear energy
Correct Answer : Heat energy

Question : A wire of resistance 20 Ω carries a current of 0.5 A. The potential difference across it is
5 V
10 V
20 V
40 V
Correct Answer : 10 V

Question : The resistance of a metallic conductor generally increases with increase in
Length only
Temperature
Cross-sectional area
Number of parallel paths
Correct Answer : Temperature

Question : A charged particle moving in a uniform magnetic field follows a helical path when its velocity is
Completely parallel to the field
Completely perpendicular to the field
At an angle other than 0° or 90° to the field
Zero
Correct Answer : At an angle other than 0° or 90° to the field

Question : A magnetic dipole placed in a uniform magnetic field is in stable equilibrium when its magnetic moment is
Perpendicular to the field
Opposite to the field
Parallel to the field
At 45° to the field
Correct Answer : Parallel to the field

Question : The self-inductance of a coil opposes a change in
Resistance
Current
Charge only
Capacitance
Correct Answer : Current

Question : An electromagnetic wave travelling in vacuum has electric and magnetic fields that are
Parallel to each other
Perpendicular to each other and to the direction of propagation
Parallel to the direction of propagation
Always zero
Correct Answer : Perpendicular to each other and to the direction of propagation

Question : An object is placed at the principal focus of a convex lens. The image is formed
At the optical centre
At twice the focal length
At infinity
Between the lens and focus
Correct Answer : At infinity