Waec Physics Past Questions

Question 21

The velocities of light in air and glass are 3.0 x10\(^8\)ms\(^{-1}\) and 1.8 \(\times \)10\(^8\) ms\(^{-1}\) respectively. Calculate the sine of the angle of incidence that will produce an angle of refraction of 30° for a ray of light incident on glass.

waec 1988

  • A. 1.2
  • B. 1.0
  • C. 0.8
  • D. 0.6
  • E. 0.3
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Question 22

A transparent rectangular block 5.0cm thick is placed on a black dot. The dot when viewed from above is seem 3.0cm from the top of the block calculate the refractive index of the material of the block.

waec 1988

  • A. 2/5
  • B. 3/5
  • C. 3/2
  • D. 5/3
  • E. 5/2
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Question 23

Which of the following statements is/are not correct about image formed by a plane mirror?

I. The magnification produced is 1

II. The image distance is same as the object distance

III. The image is real

IV. The image is laterally inverted

waec 1988

  • A. The magnification produced is 1
  • B. I only
  • C. II only
  • D. III only
  • E. I & II only
  • F. II & IV only
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Question 24

Which of the following will affect the saturation vapour pressure of a liquid?

waec 1988

  • A. Temperature of the liquid
  • B. Humidity of air
  • C. Volume of vapour
  • D. Volume of the liquid
  • E. mass of the liquid
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Question 25

Which of the following instrument may be used to measure the relative humidity?

waec 1988

  • A. Hydrometer
  • B. Barometer
  • C. Manometer
  • D. Hypsometer
  • E. Hygrometer
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