Light Reflection and Refraction Quiz

Which of the following can make a parallel beam of light when light from a point source is incident on it?

• Concave mirror as well as convex lens

• Convex mirror as well as concave lens

• Two plane mirrors placed at 90° to each other

• Concave mirror as well as concave lens

Answer explanation

A concave mirror or a convex lens can produce a parallel beam of light when light from a point source is incident on it:

A 10 mm long pin is placed vertically in front of a concave mirror. A 5 mm long image of the pin is formed at 30 cm in front of the mirror. The focal length of this mirror is

• – 30 cm

• – 20 cm

• – 40 cm

• – 60 cm

Under which of the following conditions a concave mirror can form an image larger than the actual object?

• When the object is kept at a distance equal to its radius of curvature

• When object is kept at a distance less than its focal length

• When object is placed between the focus and centre of curvature

• When object is kept at a distance greater than its radius of curvature

Answer explanation

Figure shows a ray of light as it travels from medium A to medium B. Refractive index of the medium B relative to medium A is

A light ray enters from medium A to medium B as shown in Figure 10.2. The refractive index of medium B relative to A will be

• greater than unity

• less than unity

• equal to unity

• zero

Beams of light are incident through the holes A and B and emerge out of box through the holes C and D respectively as shown in the Figure10.3. Which of the following could be inside the box?

• A rectangular glass slab

• A convex lens

• A concave lens

• A prism

A beam of light is incident through the holes on side A and emerges out of the holes on the other face of the box as shown in the Figure 10.4. Which of the following could be inside the box?

• Concave lens

• Rectangular glass slab

• Prism

• Convex lens

Which of the following statements is true?

• A convex lens has 4 dioptre power having a focal length 0.25 m

• A convex lens has –4 dioptre power having a focal length 0.25 m

• A concave lens has 4 dioptre power having a focal length 0.25 m

• A concave lens has –4 dioptre power having a focal length 0.25 m

Magnification produced by a rear view mirror fitted in vehicles

• is less than one

• is more than one

• is equal to one

• can be more than or less than one depending upon the position of the object in front of it

Rays from Sun converge at a point 15 cm in front of a concave mirror. Where should an object be placed so that size of its image is equal to the size of the object?

• 15 cm in front of the mirror

• 30 cm in front of the mirror

• between 15 cm and 30 cm in front of the mirror

• more than 30 cm in front of the mirror