Class 10 LIGHT

1.An object is placed at a distance of 0.25 m

in front of a plane mirror. The distance between the object and image will be

• 0.25 m

• (b) 1.0 m

• 0.5 m

• 0.125 m

2. The angle of incidence for a ray of light having zero reflection angle is

• 0

• 30°

• 45°

• 90°

3. For a real object, which of the following can produce a real image?

• Plane mirror

• Concave mirror

• Concave lens

• Convex mirror

5. An object at a distance of 30 cm from a

concave mirror gets its image at the same point. The focal length of the mirror is

• – 30 cm

• (b) 30 cm

• – 15 cm

• +15 cm

A concave mirror of focal length 20 cm forms an image having twice the size of object. For the virtual position of object, the position of object will be at

• 25 cm

• 40 cm

• 10 cm

• At infinity

6.The image formed by concave mirror is real, inverted and of the same size as that of the object. The position of object should be

• at the focus

• at the centre of curvature

• between focus and centre of curvature

• beyond centre of curvature

As light travels from a rarer to a denser medium it will have

• increased velocity

• decreased velocity

• decreased wavelength

• both (b) and (c)

The angle of incidence i and refraction r are equal in a transparent slab when the value of i is

• 0°

• 45°

• 90°

• depend on the material of the slab

You are given three media A, B and C of refractive index 1.33, 1.65 and 1.46. The medium in which the light will travel fastest is

• A

• B

• C

• equal in all three media

The refractive index of transparent medium is greater than one because

• Speed of light in vacuum < speed of light in tansparent medium

• Speed of light in vacuum > speed of light in tansparent medium

• Speed flight in vacuum = speed of light in tansparent medium

• Frequency of light wave changes when it moves from rarer to denser medium