## Physics Questions and Answers – Part5

41. If the spinning speed of the earth is increased then the weight of body at the equator
a. Increases
b. Decreases
c. Doubles
d. Does not change
b. Decreases

42. When the light is passed through a prism, the colour which deviates least is
a. Red
b. Green
c. Violet
d. Blue
a. Red

43. Which of the following is capillary not the reason only?
a. Rising of water from the roots of plant to its foliage
b. Blotting of ink
c. Rising of underground water
d. Spread of water drop on a cotton cloth
d. Spread of water drop on a cotton cloth

44. The focal length of convex lens is
a. The same for all the colours
b. Shorter for blue light than for red
c. Shorter for red light than for blue
d. Maximum for yellow light
b. Shorter for blue light than for red

45. The scent sprayer is based on
a. Carle’s law
b. Boyle’s law
c. Archimede’s principle
d. Bernoulli’s thereon
d. Bernoulli’s thereon

46. Magnetism at the centre of a bar magnet is
a. minimum
b. maximum
c. zero
d. minimum or maximum
c. zero

47. It is more difficult to walk on a sandy road than on a concrete road because
a. sand is soft and concreter is hard
b. the friction between sand and feet is less than that between concrete and feet
c. the friction between sand and feet is more than that between concrete and feet
d. the sand is grainy but concrete is smooth
b. the friction between sand and feet is less than that between concrete and feet

48. Find the maximum velocity for the overturn of a car moving on a circular track of radius 100 m. The co-efficient of friction between the road and tyre is 0.2
a. 0.14 m/s
b. 140 m/s
c. 1.4 km/s
d. 14 m/s
d. 14 m/s

49. Of the following properties of a wave, the one that is independent of the other is its
a. amplitude
b. velocity
c. wavelength
d. frequency
a. amplitude

50. Lux is the SI unit of
a. intensity of illumination
b. luminous efficiency
c. luminous flux
d. luminous intensity
a. intensity of illumination
Explanation:
The SI unit of intensity of illumination (illuminance) is the lux. An illuminance of 1.0 lux is produced by 1.0 lumen of light shining on an area of 1.0 m^2.