Light X grade

Untitled QuestionAssertion : For observing traffic at back, the driver

mirror is convex mirror.

Reason : A convex mirror has much larger field of

view than a plane mirror.

• Both assertion (A) and reason (R) are true and

  reason (R) is the correct explanation of assertion (A)

• Both assertion (A) and reason (R) are true and

  reason (R) is not a correct explanation of assertion(A)

• Assertion (A) is true but reason (R) is false.

• Both Assertion and Reason are false.

An object is placed at the centre of curvature of a

concave mirror. The distance between its image and the pole is

• Equal to f

• Between f and 2f

• Equal to 2f

• Greater than 2f

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

The radius of curvature of concave mirror is 12 cm. Then the focal length will be

• 12 cm

• 6 cm

• -24 cm

• -6 cm

An object is placed at a distance of 10 cm in front of a

plane mirror, then the distance of image from mirror is

• 5 cm

• 10 cm

• 20 cm

• 0 cm

Velocity of light in air is 3x108 m/s

. While its velocity

in a medium is 1.5 x 108 m/s.hen, refractive index of the medium is

• 3

• 5

• 0.5

• 2

Focal length of a plane mirror is

• Zero

• Infinite

• 25 cm

• -25 cm

An object is placed 20 cm from the concave mirror of

focal length 10 cm, then image is formed at

• behind the mirror

• between the mirror and focus

• At focus

• At centre of curvature of mirror

Parallel rays of light are reflected by a concave mirror at a point called

• Pole

• Focus

• Centre of curvature

• Aperture

Light is a form of

• Force

• Mass

• Energy

• Gravitational force