Physics MCQs Test P 14

HN PHYSICS

Prism Theory and Dispersion of Light

Q1: The critical angle between an equilateral prism and air is 45. If the incident ray is perpendicular to the refracting surface, then

  1. It is reflected totally from the second surface and emerges perpendicular from the third surface.
  2. It gets reflected from second and third surfaces and emerges from the first surface
  3. It keeps reflecting from all the three sides of the prism and never emerges out
  4. After deviation, it gets refracted from the second surface

Answer: (a) It is reflected totally from the second surface and emerges perpendicular from the third surface.



Q2: Which ray is least deviated by a prism?

  1. Violet ray
  2. Green ray
  3. Red ray
  4. Yellow ray

Answer: (c) Red ray

Q3: A prism (μ=1.5) has a refracting angle of 300. The deviation of a monochromatic ray incident normally on its one surface will be

  1. 180 36’
  2. 200 30’
  3. 180
  4. 190 30’

Answer: (a) 180 36’

Q4: The angle of the prism is equal to the angle of minimum deviation for a prism of refractive index 1.5. What is the value of the angle of the prism?

  1. 410
  2. 820
  3. 620
  4. 310

Answer: (b) 820

Q5: The dispersive power of prism depends upon

  1. The shape of the prism
  2. The material of the prism
  3. The angle of the prism
  4. Height of the prism

Answer: (b) The material of the prism

Q6: When white light passes through the achromatic combination of prism, then what is observed

  1. Dispersion
  2. Deviation
  3. Dispersion and deviation
  4. None of the above

Answer: (b) Deviation

Q7: For a wavelength l the dispersion of the medium is D, then the dispersion for the wavelength 2l will be

  1. D/8
  2. D/2
  3. 2D
  4. D

Answer: (a) D/8

Q8: The refractive angle of a prism for a monochromatic light is 600 and refractive index is √2. For minimum deviation, the angle of incidence will be

  1. 600
  2. 450
  3. 300
  4. 750

Answer: (b) 450

Q9: The dispersive power will be maximum for

  1. Flint glass
  2. Crown glass
  3. Mixture of glass
  4. None of these

Answer: (a) Flint glass

Q10: When white light is passed through a hollow prism then there is

  1. no dispersion and no deviation
  2. Only dispersion
  3. Only deviation
  4. Both dispersion and deviation

Answer: (a) no dispersion and no deviation

Wave Optics

Q1: Polarisation phenomenon explains which nature of light?

  1. Transverse
  2. longitudinal
  3. Both transverse and longitudinal
  4. geometrical

Answer: (a) Transverse

Q2: A narrow slit is taken and a parallel beam of moving electrons is incident normally on it. At a larger distance from the slit, a fluorescent screen is placed. Which of the following statement is true if the size of the slit is further narrowed?

  1. The diffraction pattern cannot be observed on the screen
  2. The angular width of the central maxima of the diffraction pattern will increase
  3. The angular width of the central maxima of the diffraction pattern will decrease
  4. The angular width of the central maxima of the diffraction pattern remains the same

Answer: (c) The angular width of the central maxima of the diffraction pattern will decrease

Q3: How does the diffraction band of blue light look in comparison with the red light?

  1. No changes
  2. Diffraction pattern becomes narrower
  3. Diffraction pattern becomes broader
  4. Diffraction pattern disappears

Answer: (b) Diffraction pattern becomes narrower

Q4: Two coherent sources of light can be obtained from

  1. Two different lamps
  2. Two different lamps but of the same colour
  3. Two different lamps of the same colour and having the same colour
  4. None of these

Answer: (d) None of these

Q5: Which of the following phenomenon is not explained by Huygen’s wave theory?

  1. Diffraction
  2. Interference
  3. Polarisation
  4. Photoelectric effect

Answer: (d) Photoelectric effect

Q6: What is the value of coherent time if L is the coherent length and c is the velocity of light?

  1. cL
  2. L/c
  3. c/L
  4. 1/Lc

Answer: (b) L/c

Q7: The ratio of the amplitude of the two sources producing interference 3 : 5, the ratio of intensities at maxima and minima is

  1. 25:6
  2. 5:3
  3. 16:1
  4. 25:9

Answer: (c) 16:1

Q8: The colours on the soap bubble is due to

  1. Interference
  2. Polarisation
  3. Diffraction
  4. Reflection

Answer: (a) Interference

Q9: Which of the following statements indicates that light waves are transverse?

  1. Light waves can be polarised
  2. Light waves can show interference
  3. Light waves undergo diffraction
  4. They travel in the vacuum

Answer: (a) Light waves can be polarised

Q10: In Young’s double-slit experiment, the phase difference between the light waves reaching the third bright fringe from the central fringe will be (λ=6000 Ã…)

  1. Zero
  2. 2Ï€
  3. 4Ï€
  4. 6Ï€

Answer: 6Ï€

Electromagnetic Spectrum

Q1: Which of the following has a minimum wavelength?

  1. Gamma rays
  2. Blue light
  3. Infrared rays
  4. microwave

Answer: (a) Gamma rays

Q2: Which among the following has the maximum penetrating power?

  1. Radio waves
  2. Microwaves
  3. Ultraviolet radiation
  4. Gamma rays

Answer: (d) Gamma rays

Q3: Which of the following is called heat radiation?

  1. X-rays
  2. Gamma rays
  3. Microwave
  4. Infrared radiation

Answer: (d) Infrared radiation

Q4: Which of the following are not electromagnetic waves?

  1. Cosmic rays
  2. Gamma rays
  3. β rays
  4. X rays

Answer: (c) β rays

Q5: 10 cm is the wavelength corresponding to the spectrum of

  1. Infrared rays
  2. Ultraviolet rays
  3. Microwaves
  4. X-rays

Answer: (c) Microwaves

Q6: The structure of solids is investigated by using

  1. Microwaves
  2. Gamma rays
  3. X-rays
  4. Infrared rays

Answer: (c) X-rays

Q7: Which radiations are used in the treatment of muscle ache?

  1. Infrared
  2. Ultraviolet
  3. Microwave
  4. X-rays

Answer: (a) Infrared

Q8: The ultra-high frequency band of radio waves in the electromagnetic wave is used as in

  1. Television
  2. Cellular phone communication
  3. Commercial FM radio
  4. Both a and b

Answer: (b) Cellular phone communication

Q9: The waves used by artificial satellites for communication is

  1. Microwaves
  2. Infrared waves
  3. Radio waves
  4. X rays

Answer: (a) Microwaves

Q10: Which of the following electromagnetic waves is used in medicine to destroy cancer cells?

  1. IR-rays
  2. Visible rays
  3. Gamma rays
  4. Ultraviolet rays

Answer: (c) Gamma rays


Perfectly Inelastic Collision

Q1: The coefficient of restitution e for a perfectly inelastic collision is

  1. 1
  2. 0
  3. Infinity
  4. -1

Answer:(b) 0

Q2: When two bodies stick together after the collision, the collision is said to be

  1. Partially elastic collision
  2. Totally elastic collision
  3. Totally inelastic collision
  4. None of the above

Answer: (c) totally inelastic

Q3: A completely inelastic collision is one in which the two colliding particles

  1. Are separated after collision
  2. Remain together after the collision
  3. Split into small fragments flying in all directions
  4. None of the above

Answer: (b) Remain together after the collision

Q4: A bullet hits and gets embedded in a solid block resting on a horizontal frictionless table. What is conserved?

  1. Momentum and kinetic energy
  2. Kinetic energy alone
  3. Momentum alone
  4. Neither momentum nor kinetic energy

Answer: (c) Momentum alone

Q5: A body of mass m moving with a constant velocity v hits another body of the same mass moving with the same velocity v but in the opposite direction and sticks to it. The velocity of the compound body after the collision is

  1. 2v
  2. v/2
  3. V
  4. Zero

Answer: (d) zero

Q6: A 50 g bullet moving with velocity 10 m/s strikes a block of mass 950 g at rest and gets embedded in it. The loss in kinetic energy will be

  1. 100%
  2. 95%
  3. 5%
  4. 50%

Answer: (b) 95%

Q7: A ball is dropped from a height 10m. The ball is embedded in sand 1m and stops, then

  1. Only momentum remains conserved
  2. Only kinetic energy remains conserved
  3. Both momentum and K.E are conserved
  4. Neither K.E nor momentum is conserved

Answer: (a) Only momentum remains conserved

Q8: Which of the following is not perfectly inelastic collision?

  1. Striking of two glass balls
  2. A bullet striking a bag of sand
  3. An electron captured by a proton
  4. A man jumping onto a moving cart

Answer: (c) An electron captured by a proton

Q9: A particle of mass m moving with velocity v strikes a stationary particle of mass 2m and stricks to it. The speed of the system will be

  1. v/2
  2. 2v
  3. v/3
  4. 3v

Answer:(c) v/3

Q10: If a skater of weight 3 Kg has initial speed 32 m/s and the second one of weight 4 kg has 5m/s. After the collision, they have speed (couple) 5 m/s. Then the loss in K.E is

  1. 48 J
  2. 96 J
  3. Zero
  4. None of these

Answer: (d) None of these


Work Done by Variable Force

Q1: There are two springs with the force constant as k1 and k2 (k1＞k2). They are stretched by the same force then

  1. More work is done in the first spring
  2. In both springs equal work is done
  3. In the second spring, more work is done
  4. No work is done in both the springs

Answer: (c) More work is done in case of the second spring

Q2: A spring with an initial stretch of  0.20 m has a force constant 10 N/m. When the stretch is changed to 0.25 m, the increase in potential energy is 

  1. 0.2 joule
  2. 0.3 joule
  3. 0.1 joule
  4. 0.5 joule

Answer: (c) 0.1 joule

Q3: Same force is used to stretch two springs of spring constants 1500 N/m and 3000 N/m respectively. What will be the ratio of potential energy?

  1. 1:4
  2. 2:1
  3. 4:1
  4. 1:2

Answer: (b) 2:1

Q4: What will be the work done in stretching the  spring through 40 mm if 10 N force is required to stretch the spring through 1 mm

  1. 68 J
  2. 23 J
  3. 84 J
  4. 8 J

Answer: (d) 8 J

Q5: A body moving with a velocity 10 m/s and having a mass 0.1 kg hits a spring (fixed at the other end) of force constant 1000 N/m and comes to rest after compressing the spring. What will be the value of compression of the spring?

  1. 0.1 m
  2. 0.2 m
  3. 0.01 m
  4. 0.5 m

Answer: (b) 0.1 m

Q6: A spring having an extension of 5 cm has a force constant 800 N/m. The work done in extending it from 5 cm to 15 cm is

  1. 16 J
  2. 8 J
  3. 32 J
  4. 24 J

Answer: (b) 8 J

Q7: 100 J of energy is stored by a spring when it is stretched by 2 cm. If it is stretched further by 2 cm, the stored energy will be increased by

  1. 100 J
  2. 200 J
  3. 300 J
  4. 400 J

Answer: (c) 300 J

Q8: The potential energy is 4 J for spring when it is stretched by 2 mm. If it is stretched by 10 mm, its potential energy is equal to

  1. 4 J
  2. 54 J
  3. 415 J
  4. 100 J

Answer: (d) 100 J

Q9: What would be the maximum compression of the spring if a mass of 0.5 kg moving on a horizontal smooth surface with a speed of 1.5 m/s  collides with a nearly weightless spring of force constant k= 5 N/m. 

  1. 0.5 m
  2. 0.12 m
  3. 1.5 m
  4. 0.15 m

Answer: (c) 0.15 m

Q10: A spring has a spring constant k. When the spring is stretched through 1 cm, the potential energy will be U. What will be the potential energy if it is stretched by 4 cm?

  1. 4 U
  2. 8 U
  3. 16 U
  4. 2 U

Answer: (c) 16 U


Uniform Circular Motion

Q1: The angular velocity of a body moving with a constant speed v in a circle of radius r is given by 

  1. v2/r
  2. vr
  3. v/r
  4. r/v

Answer: (c) v/r

Q2: A cyclist turns around a curve at 15 miles/hour. If he turns at double the speed, the tendency to overturn is

  1. Doubled
  2. Quadrupled
  3. Halved
  4. Unchanged

Answer: (b) Quadrupled

Q3: What will be the velocity vector of a particle moving in a circle describing equal angles in equal times

  1. Changes in direction
  2. Remains constant
  3. Changes in magnitude
  4. Changes both in direction and magnitude

Answer: (a) Changes in direction

Q4: A body moves with a constant speed in a circular path is moving in a circular path with a constant speed. It has

  1. Acceleration of constant magnitude
  2. Constant velocity
  3. Constant acceleration
  4. An acceleration which varies with time

Answer: (a) Acceleration of constant magnitude

Q5: A motorcyclist going with a constant speed in a circular track has 

  1. Linear velocity is constant
  2. Constant acceleration
  3. Angular velocity is constant
  4. Constant force

Answer: (c) Angular velocity is constant

Q6: What could be the reason a car moving on a horizontal road gets thrown out of the road while taking a turn

  1. Due to the reaction of the ground
  2. Due to rolling frictional force between tyre and road
  3. By the gravitational force
  4. Due to lack of sufficient centripetal force

Answer: (d) Due to lack of sufficient centripetal force

Q7: If a particle moves with constant angular velocity in a circle then during the motion its

  1. Momentum is conserved
  2. Energy is conserved
  3. Both energy and momentum is conserved
  4. None of the above is conserved

Answer: (b) Energy is conserved

Q8: A stone tied to a string is rotated in a circle. If the string is cut, the stone flies away from the circle because

  1. A centrifugal force acts on the stone
  2. Of its inertia
  3. A centripetal force acts on the stone
  4. The reaction of the centripetal force

Answer: (b) Of its inertia

Q9: A body moves with a constant speed along a circle. Then,

  1. No work is done on it
  2. There is no acceleration produced in the body
  3. No force acts on the body
  4. The body has constant velocity

Answer: (a) No work is done on it

Q10: A tachometer is a device to measure

  1. Gravitational pull
  2. Speed of rotation
  3. Surface tension
  4. Tension in a spring

Answer: (b) Speed of rotation


Horizontal Projectile Motion

Q1: A stone is just released from the window of a train moving along a horizontal straight track. The stone will hit the ground following

  1. Hyperbolic path
  2. Straight path
  3. Circular path
  4. Parabolic path

Answer: (d) Parabolic path

Q2: A bullet is dropped from the same height when another bullet is fired horizontally. They will hit the ground

  1. Simultaneously
  2. Depends on the observer
  3. One after the other
  4. None of the above

Answer: (b) Simultaneously

Q3: A bomb is dropped from an aeroplane moving horizontally at a constant speed. When air resistance is taken into consideration, the bomb

  1. Flies with the aeroplane
  2. Falls to earth behind the aeroplane
  3. Falls to earth ahead of the plane
  4. Falls to earth exactly below the aeroplane

Answer: (b) Falls to earth behind the aeroplane

Q4: The maximum range of gum on horizontal terrain is 16 km. If g = 10 m/s2. What must be the muzzle velocity of the shell?

  1. 400 m/s
  2. 100 m/s
  3. 200 m/s
  4. 50 m/s

Answer: (a) 400 m/s

Q5: An aeroplane flying 490 m above ground level at 100 m/s, releases a block. How far on the ground will it strike?

  1. 2 km
  2. 0.1 km
  3. 1 km
  4. None

Answer: (c) 1 km

Q6: A man projects a coin upwards from the gate of a uniformly moving train. The path of coin for the man will be

  1. Vertical straight line
  2. Inclined straight line
  3. Parabolic
  4. Horizontal straight line

Answer: (a) Vertical straight line

Q7: A particle A is dropped from a height and another particle B is thrown in a horizontal direction with the speed of 5m/sec from the same height. The correct statement is

  1. Particle B will reach the ground first
  2. Both particles will reach the ground with the same speed
  3. Particle A will reach the ground first
  4. Both particles will reach the ground simultaneously

Answer: (d) Both particles will reach the ground simultaneously

Q8: A particle moves in a plane with constant acceleration in a direction from the initial velocity. The path of the particle will be

  1. A parabola
  2. An ellipse
  3. A straight line
  4. An arc of a circle

Answer: (a) A parabola

Q9: An aeroplane moving horizontally with a speed of 720 km/h drops a food packet while flying at a height of 396.9m. The time taken by the food packet to reach the ground and its horizontal range is 

  1. 9 sec and 1800 m
  2. 5 sec and 500 m
  3. 8 sec and 1500 m
  4. 3 sec and 2000 m

Answer: (a) 9 sec and 1800 m

Q10: At the height 80 m, an aeroplane is moving with 150 m/s. A bomb is dropped from it so as to hit a target. At what distance from the target should the bomb be dropped

  1. 600 m
  2. 605.3 m
  3. 80 m
  4. 230 m

Answer: (a) 600 m


Optical Instruments

Q1: A lens which converges a beam of parallel rays to a point is called

  1. Diverging (or concave) lens
  2. Converging (or convex) lens
  3. Plano concave lens
  4. Plano-convex lens

Answer: (b) Converging (or convex) lens

Q2: The diameter of a lens is called

  1. Focal length
  2. Principle axis
  3. Aperture
  4. Radius of curvature

Answer: (c) Aperture

Q3: In going from a denser to rarer medium a ray of light is

  1. Undeviated
  2. Bent away from the normal
  3. Bent towards the normal
  4. polarised

Answer: (b) Bent away from the normal

Q4: The power of a concave lens is

  1. Real
  2. Virtual
  3. Positive
  4. negative

Answer: (d) negative

Q5: Magnifying power of a simple microscope

  1. Increases with increase in focal length
  2. Increases with the decrease in focal length
  3. No effect with decrease or increase with the focal length
  4. Least distance of distinct vision

Answer: (b) Increases with the decrease in focal length

Q6: Magnification of astronomical telescope is

  1. f0 + fe
  2. f0/fe
  3. fe/f0
  4. (1+f0/fe)L/f0

Answer: (b) f0/fe

Q7: The magnifying power of an astronomical telescope is 10 and the focal length of its eye-piece is 20 cm. The focal length of its objective will be

  1. 200 cm
  2. 2 cm
  3. 0.5 cm
  4. 0.5 x 10–2 cm

Answer: (a) 200 cm

Q8: The magnifying power of a telescope is 9. When it is adjusted for parallel rays, the distance between the objective and the eye-piece is found to be 20 cm. The focal lengths of the lenses are

  1. 18 cm, 2 cm
  2. 11 cm, 9 cm
  3. 10 cm, 10 cm
  4. 15 cm, 5 cm

Answer: (a) 18 cm, 2 cm

Q9: In a compound microscope, magnifying power is 95 and the distance of the object from the objective lens is 1/38 cm. The focal length of the objective lens ¼ cm. What is the magnification of eyepiece?

  1. 5
  2. 10
  3. 100
  4. 200

Answer: (a) 5

Q10: A hypermetropic person having “near point” at a distance of 0.75 m puts on spectacles of power 2.5 D. The “near point” now is at

  1. 0.75 m
  2. 0.83 m
  3. 0.26 cm
  4. 0.26 m

Answer: (d) 0.26 m


Logic Gates

Q1: An inverter gates can be developed using

  1. Two diodes
  2. Resistance and capacitance
  3. Transistor
  4. Inductance and capacitance

Answer: (c) Transistor

Q2: The output of the two-input OR gate is high

  1. Only if both inputs are high
  2. Only if both inputs are low
  3. Only if one input is high and the other is low
  4. If at least one of the inputs is high

Answer: (d) If at least one of the inputs is high

Q3: The output of a two-input AND gate is high

  1. Only if both the inputs are high
  2. Only if both the inputs are low
  3. Only if one input is high and the other is low
  4. If at least one input is low

Answer: (a) Only if both the inputs are high

Q4: NAND gate means

  1. Inversion followed by AND gates
  2. AND gates followed by an inverter
  3. AND gate followed by OR gate
  4. None of these

Answer: (b) AND gates followed by an inverter

Q5: The output of the two-input NAND gate is high

  1. Only if both the inputs are high
  2. Only if both the inputs are low
  3. Only if one input is high and the other is low
  4. If at least one input is low

Answer: (d) If at least one input is low

Q6: A NOR gate means

  1. Inversion followed by an OR gate
  2. OR gate followed by an inverter
  3. NOT gate followed by an OR gate
  4. NAND gate followed by an OR gate

Answer: (b) OR gate followed by an inverter

Q7: The output of two-input NOR gate is high

  1. Only if both the inputs are high
  2. Only if both the inputs are low
  3. Only if one input is high and the other is low
  4. If at least one input is high

Answer: (b) Only if both the inputs are low

Q8: An exclusive NOR gate is logically equal to

  1. Inverter followed by an XOR gate
  2. NOT gate followed by an exclusive XOR gate
  3. Exclusive OR gate followed by an inverter
  4. The complement of a NOR gate

Answer: (c) Exclusive OR gate followed by an inverter

Q9: The gate ideally suited for bit comparison is a

  1. Two input exclusive NOR gate
  2. Two input exclusive OR gate
  3. Two input NAND gate
  4. Two input NOR gate

Answer: (a) Two input exclusive NOR gate

Q10: Two input exclusive NOR gate gives high output

  1. When one input is high and the other is low
  2. Only when both the inputs are low
  3. When both the inputs are the same
  4. Only when both the inputs are high

Answer: (c) When both the inputs are the same

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