Light and Optics Worksheet (Set 2)
Q2. Short Answer Type Questions:
a. Evaluate the significance of dispersion in natural phenomena.
Dispersion of light causes the formation of a rainbow and gives color to the sky.
b. The concave reflecting surface of a torch got rusted. What effect would this have on the beam of light from the torch?
The rusted surface will scatter and absorb light irregularly, causing the beam to be dim and unable to cover a large distance.
c. Samarth made light from a laser torch fall on a prism. Will he be able to observe a band of seven colors? Explain with a reason.
No, he will not observe a band of seven colors because a laser beam is a single-wavelength light, unlike white light which contains multiple wavelengths that can be dispersed by a prism.
d. A person is standing 5 meters away from a plane mirror. If the person moves closer by 1 meter, what is the new distance between the person and their image?
Initially, the distance between the person and the image is: 5m + 5m = 10m. If the person moves 1m closer, the new distance will be 4m + 4m = 8m.
e. What type of mirrors create distorted images in amusement parks?
Spherical mirrors (Concave and Convex mirrors).
f. A student suggests using a convex mirror to focus sunlight to start a fire. Is this suggestion correct? Why or why not?
No, this suggestion is incorrect. A convex mirror diverges light rays, whereas a concave mirror converges light rays to a single point, which can be used to start a fire.
g. If light strikes a rough surface, will the law of reflection still apply? Justify your answer.
Yes, the laws of reflection apply in all situations. However, due to the irregular surface, the reflected rays scatter in different directions, causing diffused reflection.
h. Where should a dentist place a concave mirror to get a magnified image of a tooth?
A dentist should place the concave mirror close to the tooth, between the focal point and the mirror, to obtain a magnified and erect image.