LIGHT REFLECTION AND REFRACTION

1. When an object moves closer to a concave lens, the Image formed by it shifts

• Away from the lens

• Towards the lens

• First away and then towards the lens

• First towards and then away from the lens

2. An object AB is placed in front of a convex Lens at its principal focus The image will be formed at

• focus

• beyond C

• Between F & C

• infinity

3. What is the angle between the incident and reflected rays when a ray of light is incident normally on a plane mirror?

• 90⁰

• 45⁰

• 180⁰

• 0⁰

4. An object is placed 40.0 cm in front of a convex mirror. The image appears 15 cm behind the mirror. What is the focal length of the mirror?

• -24

• -11

• +11

• +24

The refractive index of dens flint glass is 1.65 and for alcohol, it is 1.36 with respect to air, then the refractive index of the dens flint glass with respect to alcohol is

• 1.31

• 1.21

• 1.11

• 1.01

A virtual image three times the size of the object is obtained with a concave mirror of radius of curvature 36 cm. The distance of the object from the mirror is

• 20 cm

• 10 cm

• 12 cm

• 5 cm

Refractive index of diamond with respect to glass is 1.6. If the absolute refractive index of glass is 1.5, then the absolute refractive index of diamond is

• 1.4

• 2.4

• 3.4

• 4.4

As the velocity of light increases, the refractive index of the medium decreases. Light enters from air to water having refractive index 4/3. Find the speed of light in water. The speed of light in vacuum is 3 x 10 ^8 m/s.

• 3.75 x 10 ^8 m/s.
  

• 2.25 x 10 ^8 m/s.
  

• 4.25 x 10 ^8 m/s.
  

• 4.75 x 10 ^8 m/s.
  

A doctor has prescribed a corrective lens of power +1.5 D. Find the focal length of the lens. Is the prescribed lens diverging or converging?

• 15.7 , Converging

• 75. 5, Diverging

• 66.7 Converging

• 0.33 Diverging

A convex lens forms a real and inverted image of a needle at a distance of 50 cm from it. Where is the needle placed in front of the lens, if image size is equal to the object size? Also, find the power of the lens.

• +6D

• +5D

• +4D

• +3D