When an object is placed at a distance of 60 cm from a convex mirror, the magnification produced is 1 2 . Where should the object be placed to obtain a magnification of 1 3 ?

Given, The initial object distance, u 1 = - 60 cm , the initial magnification, m 1 = 1 2 and the final magnification, m 2 = 1 3 . Say, the final object distance is u 2 , and the focal length of the mirror is f . We know that the magnification is given by, m = f ( f − u ) Hence, by substituting the data, we get, m 1 = f ( f − u 1 ) ⇒ 1 2 = f f + 60 ⇒ f = 60 cm The magnification in the second case will be, m 2 = f ( f − u 2 ) ⇒ 1 3 = 60 60 - u 2 ⇒ u 2 = - 120 cm Hence, the object is placed at a distance of 120 cm in front of the mirror.

Match the corresponding entries of column- 1 with column- 2 . (Where m is the magnification produced by the mirror) Column-1 Column-2 (A) m = − 2 (p) Convex mirror (B) m = − 1 / 2 (q) Concave mirror (C) m = + 2 (r) Real image (D) m = + 1 / 2 (s) Virtual image

A → q and r ; B → q and r ; C → q and s ; D → p and s

A → p and r ; B → p and s ; C → p and q ; D → r and s

A → p and s ; B → q and r ; C → q and s ; D → q and r

A → r and s ; B → q and s ; C → q and r ; D → p and s

MEDIUM

12th ICSE

IMPORTANT

Earn 100

The image formed by a convex mirror of radius of curvature $20 cm$ is half the size of the object. Find the position of the object and of its image.

Important Questions on Reflection of Light : Spherical Mirrors

MEDIUM

12th ICSE

IMPORTANT

ISC Physics Class 12, Part-2>Chapter 1 - Reflection of Light : Spherical Mirrors>QUESTIONS>Q 12

When an object is placed at a distance of

60 cm

from a convex mirror, the magnification produced is

\frac{1}{2}

. Where should the object be placed to obtain a magnification of

\frac{1}{3}

MEDIUM

12th ICSE

IMPORTANT

ISC Physics Class 12, Part-2>Chapter 1 - Reflection of Light : Spherical Mirrors>For DIFFERENT COMPETITIVE EXAMINATIONS>Q 1

A beam of light from a source $L$ is incident normally on a plane mirror fixed at a certain distance $x$ from the source. The beam is reflected back as a spot on a scale placed just above the source $L$ . When the mirror is rotated through a small angle $θ$ , the spot of the light is found to move through a distance $y$ on the scale. The angle $θ$ is given by:

HARD

12th ICSE

IMPORTANT

ISC Physics Class 12, Part-2>Chapter 1 - Reflection of Light : Spherical Mirrors>For DIFFERENT COMPETITIVE EXAMINATIONS>Q 2

A ray of light travelling in the direction

\frac{1}{2} (\hat{i} + \sqrt{3} \hat{j})

is incident on a plane mirror. After reflection, it travels along the direction

\frac{1}{2} (\hat{i} - \sqrt{3} \hat{j})

. The angle of incidence is:

MEDIUM

12th ICSE

IMPORTANT

ISC Physics Class 12, Part-2>Chapter 1 - Reflection of Light : Spherical Mirrors>For DIFFERENT COMPETITIVE EXAMINATIONS>Q 3

An object is placed at a distance of $40 cm$ from a concave mirror of focal length $15 cm$ . If the object is displaced through a distance of $20 cm$ towards the mirror, the displacement of the image will be:

HARD

12th ICSE

IMPORTANT

ISC Physics Class 12, Part-2>Chapter 1 - Reflection of Light : Spherical Mirrors>For DIFFERENT COMPETITIVE EXAMINATIONS>Q 4

In an experiment to determine the focal length (

f

) of a concave mirror by the

u - v

pin method, a student places the object pin

A

on the principal axis at a distance

x

from the pole

P

. The student looks at the pin and its inverted image from a distance keeping his/her eye in line with

P A

. When the student shifts his/her eye towards left, the image appears to the right of the object pin. Then:

HARD

12th ICSE

IMPORTANT

ISC Physics Class 12, Part-2>Chapter 1 - Reflection of Light : Spherical Mirrors>For DIFFERENT COMPETITIVE EXAMINATIONS>Q 5

A car is fitted with a convex side-view mirror of focal length

20 cm

. A second car

2.8 m

behind the first car is overtaking the first car at a relative speed of

15 m s^{- 1}

. The speed of the image of the second car as seen in the mirror of the first one is:

HARD

12th ICSE

IMPORTANT

ISC Physics Class 12, Part-2>Chapter 1 - Reflection of Light : Spherical Mirrors>For DIFFERENT COMPETITIVE EXAMINATIONS>Q 6

A wire is bent in the shape of a right angled triangle and is placed in front of a concave mirror of focal length $f$ , as shown in the figure. Which of the figures shown in the four options qualitatively represent(s) the shape of the image of the bent wire? (These figures are not to scale).

Question Image

HARD

12th ICSE

IMPORTANT

ISC Physics Class 12, Part-2>Chapter 1 - Reflection of Light : Spherical Mirrors>For DIFFERENT COMPETITIVE EXAMINATIONS>Q 7

Match the corresponding entries of column- $1$ with column- $2$ . (Where $m$ is the magnification produced by the mirror)

	Column-1		Column-2
(A)	$m = - 2$	(p)	Convex mirror
(B)	$m = - 1 / 2$	(q)	Concave mirror
(C)	$m = + 2$	(r)	Real image
(D)	$m = + 1 / 2$	(s)	Virtual image

The image formed by a convex mirror of radius of curvature 20 cm is half the size of the object. Find the position of the object and of its image.

Important Questions on Reflection of Light : Spherical Mirrors

Learn and Prepare for any exam you want !

The image formed by a convex mirror of radius of curvature $20 cm$ is half the size of the object. Find the position of the object and of its image.