light, heat, thermodynamics, wave motion, sound, optics & oscillations - Category wise Question and Answer Practice Test with Solutions

Question : 21 [IAS (Pre) 2000]

Assertion (A):
In a motion picture, usually 24 frames are projected every second over the whole length of the film.
Reason (R):
An image formed on the retina of eye persists for about 0.1s after the removal of the stimulus.
Code

a) (A) is true, but (R) is false

b) Both (A) and (R) are true, but (R) is not the correct explanation of (A)

c) Both (A) and (R) are true and (R) is the correct explanation of (A)

d) (A) is false, but (R) is true

Question : 22

In lateral inversion

a) upside of the object will be down side of the object.

b) right side of the object will be right side of the image.

c) left side of the object will be left side of the image.

d) right side of the object will be left side of the image.

Question : 23 [IAS (Pre) 1995]

Let the average temperatures in Centigrade (C) and Fahrenheit (F) be $C↖{-}$ and $F↖{-}$ . If $C↖{-}$ and $F↖{-}$ are related to F = $9/2$C + 32, then $F↖{-}$ and $C↖{-}$ have the relation

a) $F↖{-} = C↖{-}$ + 32

b) $F↖{-} = 9/2 C↖{-}$

c) $F↖{-}= 9/5 C↖{-}$ + 32

d) $F↖{-} = 9/5C↖{-}$ - 32

Question : 24

Consider the following statements:

1. Light has transverse wave nature.
2. Light cannot travel in vacuum.
3. No particle can ever move at a speed greater than the speed of light in vacuum.

a) 2 and 3

b) 1 and 2

c) 1 and 3

d) 1, 2 and 3

Question : 25

Consider the following statements:

1. Light of longer wavelength are scattered much more than the light of shorter wavelength.
2. The speed of visible light in water is 0.95 times the speed in vacuum.
3. Radio waves are produced by rapidly oscillating electrical currents.
4. To detect the over speeding vehicles, police use the Doppler effect of reflected short radio waves.

a) 2 and 4

b) 1 and 2

c) 1 and 3

d) 3 and 4