Light Test - 7...

Two plane mirrors, A and B, are kept at an angle θ with respect to each other.

The light falling on A gets reflected. Then it falls on B and again gets reflected. The direction of emergent ray is opposite to that of the incident ray. What is the value of angle θ?

Read the following statements and choose the correct option accordingly:

Statement A: Reflection from the water surface is diffused reflection.
Statement B: In diffused reflection, a parallel beam, after reflection, does not remain parallel.

What will be the total number of images formed if an object is placed symmetrically between two plane mirrors inclined at an angle of 72° with respect to each other?

Two plane mirrors are inclined with respect to each other at some angle. A ray of light is incident at 45° on one; after reflection from the second mirror, it retraces its path. The angle between the mirrors is

A beam of light is incident at an angle of 30° on a plane mirror. The mirror is then rotated by an angle of 20°.

By what angle will the reflected beam rotate?

An object is moving towards a plane mirror with a velocity of 2 m/s. At what speed does the image approach the object?

A star is present between two vertical barriers, a little above a plane horizontal mirror, as shown below:



From which points would an observer be able to see the star?

Read the following statements and choose the correct option accordingly:

Statement A: Refractive index determines the optical density of a medium.
Statement B: Refractive index is independent of the wavelength of the light.

Light is travelling from glass into water. The speed of light in glass is 2 × 10⁸ m/s and the speed of light in water is 2.5 × 10⁸ m/s. The refractive index of water with respect to glass is

Read the following statements and choose the correct option accordingly.

Statement A: During the propagation of light from a denser medium to a rarer medium, light bends away from the normal.
Statement B: During refraction, there is no change in the frequency of light.

Read the following statements and choose the correct option accordingly.

Statement A: Two vessels, A and B, are filled to the brim. Vessel A is filled with alcohol and vessel B is filled with water. The base of the vessel B will look deeper.
Statement B: The refractive index of alcohol is less than that of water.

A diver in a swimming pool wants to signal his distress to a person lying on the edge of the pool by flashing his water-proof flashlight. Which of the following would be the best way to give that signal?

An object, placed at infinity, starts moving towards a convex lens. As it approaches the centre of curvature, the speed of the image is _____ as compared to that of the object, and the size of the image is _____ as compared to that of the object. As the object moves from centre of curvature towards the focus, the speed of the image is _____ as compared to that of the object, and the size of the image is _____ as compared to that of the object.

An object is placed at a distance of 20 cm from a convex lens of focal length 10 cm. At what distance from the lens is the image formed?

Read the following statements and choose the correct option accordingly.

Statement A: A lens forms a virtual image having half the size of an object placed at 2 m.
Statement B: The lens used is a concave lens of focal length 2 m.

A ray of light incidents on a plane mirror at an angle of 30°. The deviation produced in the ray (in degrees) is

Which of the following statements is/are true for irregular reflection?

In a military training exercise, three teams are stationed at points A, B and C, as shown below, with a hillock between teams A and C. Team A sends a light signal to B, which has to reflect it to team C, so that all the three teams start the exercise simultaneously. What should be the angle of the reflecting mirror, held by team B?

Ram stands at 'A' on the side of a plane mirror as shown in the above diagrams. He cannot see himself, but can see Raju at 'P' and Sham at 'Q'. Which of the ray diagrams given above correctly explains the situation?

Which of the following is NOT true about an image formed by a plane mirror?