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BPSC General Science - Physics Question Bank

BPSC General Science – Physics Question Bank of BPSC Previous Year’s Papers for preparation of BPSC Prelims and other Bihar state examinations.

1. Which of the following is not a vector quantity ? (BPSC – 2001)

(a) Displacement
(b) Velocity
(c) Force
(d) Volume

Correct Answer –  (d) Volume

  • A vector quantity is determined by both magnitude and direction. 
  • A scalar quantity can only be determined by its magnitude.
  • Thus displacement, velocity and force are the examples of vector quantity while volume is a scalar quantity.

2. Which physical quantity is represented by the ratio of momentum and velocity of the body? (BPSC – 2001)

(a) Velocity
(b) Acceleration
(c) Mass
(d) Force

Correct Answer – (c) Mass

  • Momentum is a vector quantity that is the product of Mass and the Velocity of an object or particle.
  • Momentum = Mass × Velocity
  • So, Mass = Momentum / Velocity

3. Force is the product of ? (BPSC – 2001)

(a) Mass and velocity
(b)Mass and acceleration
(c) Weight and velocity
(d) Weight and acceleration

Correct Answer –  (b)Mass and acceleration

  • Force is the product of Mass and Acceleration of an object on which force is applied.
  • Force = Mass x Acceleration
  • F = M * A

4. Spherical form of raindrop is due to which among the following ? (BPSC – 1994)

(a) Density of liquid
(b) Surface tension
(c) Atmospheric pressure
(d) Gravitational force

Correct Answer –  (b) Surface tension

  • Surface tension is the tendency of liquid surfaces at rest to shrink into the minimum surface area possible.
  • The shape of a drop of rain is affected by the surface tension, which tries to give it the shape for which the surface area is minimum for the given volume. 
  • As the spherical shape has the minimum surface area, rain drops acquire spherical shape.

5. At which temperature density of water is maximum? (BPSC – 1998)

(a) 4°C
(b) 0°C
(c) -4°C
(d) -8°C

Correct Answer –  (a) 4°C

  • The mass of any substance on heating remains the same however its volume increases. Thus, it leads to a decrease in  density.
  • However, water exhibits an anomalous behavior.
  •  When water is heated from 0°C to 4°C, its volume decreases and thus density increases. Hence, at 4°C, the volume of water is minimum and density of water is maximum.
  • This increase in volume of water when cooled from 4°C to 0°C is known as Anomalous expansion of water.

6. The visible range of solar radiation is ? (BPSC – 2011)

(a) 100-400 nm
(b) 400-700 nm
(c) -740-10000 nm
(d) None of the above

Correct Answer –   (b) 400-700 nm

  • The electromagnetic spectrum is divided into three ranges:
    • Ultraviolet → Below 400 nm
    • Visible  → 400 to 700 nm 
    • Infrared → Above 700 nm

7. The nature of radiation of light is ? (BPSC – 1998)

(a) Like wave
(b) Like particle
(c) Like both of wave and particle
(d) Like neither of wave nor of particle

 

Correct Answer –  (c) Like both of wave and particle

  • The light has a dual nature.
  • Sometimes it behaves only as waves and sometimes as particles. 
  • Initially light was considered only as a wave however after the studies of  black body radiation and the photoelectric effect which proved the particle nature of light, it was concluded that light has dual nature.

8. The time taken by sunlight to reach up to the surface of earth is approximately ? (BPSC – 1997)

(a) 4.2 minutes
(b) 4.8 sec
(c) 8.5 minutes
(d) 3.6 hrs

Correct Answer –  (c) 8.5 minutes

  • Sunlight takes about 8 minutes and 20 seconds to reach Earth’s surface.

9. Sky looks blue because ? (BPSC – 1994)

(a) Blue color in the sunlight is more than other colours
(b) Short waves are scattered more than long waves by atmosphere
(c) Blue colour is more absorbing to eyes
(d) Atmosphere absorbs long wavelength more than short wavelength

Correct Answer –  (b) Short waves are scattered more than long waves by atmosphere

  • Sunlight is made up of a spectrum of colors which includes red, yellow, green, blue, and violet. 
  • Each color has a different wavelength, with blue and violet having the shortest wavelengths.
  • When sunlight passes through the Earth’s atmosphere, the air molecules scatter the light in all directions. In this process, Blue light is scattered the most as it has a shorter wavelength.
  • When we look at the sky, it is the scattered light which enters the eyes. As blue is the most scattered light, Sky looks blue.

10. Sea seems blue due to ? (BPSC – 1995)

(a) Excess deepness
(b) Reflection of sky and scattering of light by water molecules
(c) Blue colour of water
(d) Upper layer of water

Correct Answer –  (b) Reflection of sky and scattering of light by water molecules

  • The sea looks blue for the same reason the sky looks blue that is due to the refraction and scattering of light rays.

11. For shaving, one uses which among the following ? (BPSC – 1999)

(a) Concave mirror
(c) Convex mirror
(b) Plain mirror
(d) None of these

Correct Answer –  (a) Concave mirror

  • A concave mirror of a large focal length is used for shaving as it produces a magnified and erect image of the face, which makes it easier to shave.

12. Light is made of seven colours. What is the method of separating the colours ? (BPSC – 2005)

(a) The colours can be separated by a prism
(b) The colours can be separated by a filter
(c) The colours can be separated by plants
(d) The colours cannot be separated

Correct Answer –  (a) The colours can be separated by a prism

  • The white colour is made up of seven colours.
  • When it passes through a prism, different colours of light are refracted by a different amount because of different wavelengths and appear separately.

13. In which direction the rainbow is seen at 12 noon ? (BPSC – 1999)

(a) In the West
(b) In the South
(c) In the East
(d) It cannot be seen

Correct Answer –  (d) It cannot be seen

  • Rainbows are an optical phenomenon that are caused because of sunlight passing through raindrops and dispersing into a spectrum of colors.
  • However, Rainbows are not visible at 12 noon as the sun is directly overhead.
  • For the rainbow phenomena to occur, the sun needs to be less than 42° above the horizon.

14. To remove the defect of long sightedness one uses ?

(a) Concave lens
(b) Convex mirror
(c) Convex lens
(d) Concave mirror

Correct Answer –  (c) Convex lens

  • Long-sightedness:
      • It is also known as hyperopia or hypermetropia.
      • It is an eye condition in which distant objects are usually seen clearly, but close objects are not visible clearly.
      • To remove this vision problem, convex lenses are used.
  • Short-sightedness:
    • It is also known as myopia.
    • It is an eye condition in which close objects are usually seen clearly, but distant objects are not visible clearly.
    • To remove this vision problem, concave lenses are used.

15. Reading glasses are made from which type of lenses ?(BPSC – 2000)

(a) Concave
(b) Convex
(c) Plain
(d) None of these

Correct Answer –  (b) Convex

  • A convex lens, also called a converging lens, is used in reading glasses.
  • It is also used to remove the defect of long-sightedness.

16. In winter you touch a log of wood and a rod of iron, you will feel the rod of iron is colder because ? (BPSC – 1996)

(a) The heat of rod of iron is less than the heat of log of wood
(b) In comparison to wood, iron is good conductor of heat
(c) In comparison to wood, iron is bad conductor of heat
(d) The rod of iron is heavier than the log of wood

Correct Answer – (b) In comparison to wood, iron is good conductor of heat

  • In comparison to wood, iron is a good conductor of heat. 
  • When both the metal and the wood are at the same temperature, heat will be lost from iron faster hence it will feel colder as compared to wood.

17. By opening the door of the refrigerator kept in the room ? (BPSC – 1994)

(a) You can cool the room to some degree
(b) You can cool the room to the temperature of refrigerator
(c) You can warm the room a little
(d) You can neither cool nor warm the room

Correct Answer –  (c) You can warm the room a little

  • If the door of a refrigerator is left open in a room, the temperature will start to rise inside the refrigerator. 
  • To reduce the temperature, the thermostat will start which will  try to cool it back down. 
  • Due to this running of the thermostat motor, heat will be generated in the room which will result in a warmer room.

18. Cosmic rays ? (BPSC -2015)

(a) Are charged particles
(b) Are uncharged particles
(c) Can be charged as well as uncharged
(d) None of the above

Correct Answer –  (a) Are charged particles

  • Cosmic rays are immensely high-energy particles, mainly originating outside the solar system.
  • Cosmic rays can come from the sun, other stars, supernovae, and even distant galaxies.

19. What is the distance between two successive crests or successive troughs called ? (BPSC – 2002)

(a) Amplitude
(b) Wavelength
(c) Frequency
(d) None of these

Correct Answer – (b) Wavelength

  • The distance between two successive crests or successive troughs is called Wavelength of a wave.
  • The number of waves that pass a given point in one second is called the frequency of a wave.
  • The distance between the center line and the top of a crest or the bottom of a trough is called the amplitude of a wave.

20. Which among the following rays are used in the diagnosis of intestinal diseases ?

(a) X-rays
(c) Beta-rays
(b) Alpha-rays
(d) Gamma-rays

Correct Answer – (a) X-rays

  • X-rays are a type of electromagnetic radiation that have the capacity to pass through most objects, including the human body.
  • Hence, they are used in the diagnosis of intestinal diseases to create images of the body inside.

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