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Question (1)

QN0036272

The principal focus of a concave mirror is the point where

(A) parallel rays appear to diverge
(B) parallel rays actually meet after reflection
(C) reflected rays become parallel
(D) incident rays are absorbed

Correct Answer: B

Explanation:

Parallel rays incident on a concave mirror converge at its principal focus after reflection.

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Question (2)

QN0036273

A spherical mirror has a radius of curvature of 36 cm. Its focal length is

(A) 9 cm
(B) 18 cm
(C) 36 cm
(D) 72 cm

Correct Answer: B

Explanation:

For a spherical mirror, f = R/2 = 36/2 = 18 cm.

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Question (3)

QN0036274

An object is placed 36 cm in front of a concave mirror having a focal length of 12 cm. The image is formed at

(A) 18 cm in front of the mirror
(B) 12 cm behind the mirror
(C) 24 cm behind the mirror
(D) 36 cm behind the mirror

Correct Answer: A

Explanation:

Using 1/v + 1/u = 1/f, with u = -36 cm and f = -12 cm, v = -18 cm. Thus, the image is formed 18 cm in front.

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Question (4)

QN0036275

When an object is placed at the centre of curvature of a concave mirror, the image formed is

(A) virtual, erect and enlarged
(B) real, inverted and same size
(C) real, erect and diminished
(D) virtual, inverted and same size

Correct Answer: B

Explanation:

An object at the centre of curvature forms a real, inverted image of the same size at the centre of curvature.

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Question (5)

QN0036276

An object is placed 30 cm in front of a concave mirror having focal length 15 cm. The magnification is

(A) +1
(B) -1
(C) +2
(D) -2

Correct Answer: B

Explanation:

Using the mirror formula, v = -30 cm. Therefore m = -v/u = -(-30)/(-30) = -1.

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Question (6)

QN0036277

A concave mirror has focal length -24 cm and an object is placed 60 cm in front of it. The image distance is

(A) -40 cm
(B) +40 cm
(C) -20 cm
(D) +20 cm

Correct Answer: A

Explanation:

Using 1/v + 1/u = 1/f, with u = -60 cm and f = -24 cm, v = -40 cm.

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Question (7)

QN0036278

An object is placed between the focus and pole of a concave mirror. The image formed is

(A) real, inverted and diminished
(B) real, inverted and enlarged
(C) virtual, erect and enlarged
(D) virtual, inverted and diminished

Correct Answer: C

Explanation:

When the object lies between F and P of a concave mirror, the image is virtual, erect and enlarged behind the mirror.

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Question (8)

QN0036279

A convex mirror has focal length 20 cm and an object is placed 30 cm in front of it. The image distance is

(A) +12 cm
(B) -12 cm
(C) +60 cm
(D) -60 cm

Correct Answer: A

Explanation:

Using the mirror formula with f = +20 cm and u = -30 cm gives v = +12 cm.

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Question (9)

QN0036280

The image formed by a convex mirror for a real object is always

(A) real, inverted and enlarged
(B) real, erect and diminished
(C) virtual, erect and diminished
(D) virtual, inverted and enlarged

Correct Answer: C

Explanation:

A convex mirror always forms a virtual, erect and diminished image for a real object.

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Question (10)

QN0036281

Convex mirrors are commonly used as rear-view mirrors because they

(A) form enlarged images
(B) form real images
(C) provide a wider field of view
(D) have a very short focal length

Correct Answer: C

Explanation:

A convex mirror provides a wider field of view and therefore allows the driver to see more area behind the vehicle.

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Question (1)

The principal focus of a concave mirror is the point where

Explanation:

Link:

Question (2)

A spherical mirror has a radius of curvature of 36 cm. Its focal length is

Explanation:

Link:

Question (3)

An object is placed 36 cm in front of a concave mirror having a focal length of 12 cm. The image is formed at

Explanation:

Link:

Question (4)

When an object is placed at the centre of curvature of a concave mirror, the image formed is

Explanation:

Link:

Question (5)

An object is placed 30 cm in front of a concave mirror having focal length 15 cm. The magnification is

Explanation:

Link:

Question (6)

A concave mirror has focal length -24 cm and an object is placed 60 cm in front of it. The image distance is

Explanation:

Link:

Question (7)

An object is placed between the focus and pole of a concave mirror. The image formed is

Explanation:

Link:

Question (8)

A convex mirror has focal length 20 cm and an object is placed 30 cm in front of it. The image distance is

Explanation:

Link:

Question (9)

The image formed by a convex mirror for a real object is always

Explanation:

Link:

Question (10)

Convex mirrors are commonly used as rear-view mirrors because they

Explanation:

Link:

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