NDA 2013 (2) - Solved Paper

Solved Question Paper - General Knowledge of NDA Exam held on 11.08.2013

69. Power required by a boy of mass 30 kg to run up a staircase of 40 steps in 10 seconds is (Height of each step is 15 cm) (Take g = 10 m/s2)

  1. 1800 Watt
  2. 180 Watt
  3. 18000 Watt
  4. 18 Watt

70. q65
The figure given above shows the temperature (T) – Time (t) plot when we start heating a piece of naphthalene. The temperature (T*) at the plateau of the curve signifies

  1. boiling point of naphthalene.
  2. freezing point of naphthalene.
  3. melting point of naphthalene.
  4. the temperature when naphthalene undergoes a chemical change upon heating.

71. A piece of paper and a coin both having the same mass are dropped from the 10th floor of a building. The piece of paper would take more time to reach the ground because

  1. gravitational pull on the paper is less than the coin.
  2. buoyant force on the piece of paper is more than that on the coin.
  3. buoyant force on the coin is more and acts in the downward direction.
  4. the piece of paper takes a longer path to reach the ground.

72. During sunrise and sunset, sun appears reddish-orange because

  1. during that time sun emits only reddish-orange light.
  2. all other colours are absorbed by the atmosphere.
  3. reddish-orange light is least scattered by the atmosphere.
  4. all other colours apart from reddish-orange are reflected back by the atmosphere.

73. Ohm’s law can also be taken as a statement for

  1. conservation of energy.
  2. conservation of electric charge.
  3. conservation of angular momentum.
  4. non-conservation of momentum of the flowing charges.

74. Motion, of a particle can be described in x-direction by x = a sin ωt, and y-direction by y = b cos ωt. The particle is moving on

  1. a circular path of radius ‘a’.
  2. a circular path of radius ‘b’
  3. an elliptical path.
  4. a straight line.

75. q75
The plot given above represents displacement ‘x’ of a particle with time ‘t’. The particle is

  1. moving with uniform velocity.
  2. moving with acceleration.
  3. moving with deceleration.
  4. executing a periodic motion.

76. A bullet of mass 20 gm is fired in the horizontal direction with a velocity 150 m from a pistol of mass 1 kg. Recoil velocity of the pistol is

  1. 3 m/s
  2. 3 km/s
  3. 300 m/s
  4. 1/3 m/s

77. q77
What should be the reading of the voltmeter in the circuit given above? (All the resistances are are equal to 1 Ω and the battery is of 1.5 volt)

  1. 1.5 volt
  2. 0.66 volt
  3. 1 volt
  4. 2 volt

78. q78
The plot given above represents the velocity of a particle (in m/s) with time (in seconds). Assuming that the plot represents a semi-circle distance traversed by the particle at the end of 7 seconds is approximately

  1. 19 m
  2. 7 m
  3. 3-2 m
  4. 4-75 m

79. Suppose we have an iron nail and an iron ball of same mass. When submerged in water, the iron ball may float but the nail always sinks. This is because

  1. buoyant force on the ball is larger than that of the nail due to their shapes.
  2. Viscous force on the ball is higher.
  3. viscous force on the nail is higher.
  4. gravitational force affects the ball differently from the nail.

80. An electric heater is rated 1500 watt. If electric power costs Rs 2 per kilo-watt-hour, then the cost of power for 10 hours running of the heater is

  1. Rs 30
  2. Rs 15
  3. Rs 150
  4. Rs 25

81. The ceilings of a concert hall are generally curved

  1. because they reflect the sound to the audience.
  2. because they can absorb noise.
  3. to have better aeration in the hall.
  4. as any sound from outside cannot pass through a curved ceiling.

82. Bats can know about their prey at a distance even in the night by emitting

  1. infra-red lights.
  2. ultraviolet lights.
  3. chemicals from their body.
  4. ultrasonic sounds.

83. Rays of light get refracted while passing from air to glass because

  1. density of glass is higher than that of air.
  2. they cannot be reflected from a glass surface.
  3. glass absorbs energy from the light rays.
  4. speed of light in glass is less than the speed of light in air.

84. White light while passing through a glass prism breaks up into light of different colours because

  1. refractive index of glass for different colours of light is different.
  2. glass prism absorbs white light and emits lights of several colours in different directions.
  3. of total internal reflection of white light on surfaces of the prism.
  4. of the interference of different colours inside the prism.

85. q85
Which one among the following situations is best represented by the velocity – time plot shown above?

  1. Uniform motion of a particle on a circle
  2. Accelerated motion of a particle which has a non-zero initial velocity
  3. Decelerated motion of a particle which has an initial non-zero velocity
  4. Decelerated motion of a which has no initial velocity

86. When long dry hair is brushed the strands often move away from each other because while brushing

  1. air is being blown through the strands.
  2. static electric charges are being induced on the hair.
  3. mechanical energy is being transferred into heat energy.
  4. the gravitational attraction among the strands becomes smaller.