Find the focal length of a convex spherical mirror which produces an image 1 6 th the size of an object located 0 . 12 m from the mirror?

Object distance, u = - 0 . 12 m . Since the mirror is convex, the image is virtual and erect. So magnification will be positive. From the given information, magnification m = 1 6 . Also, m = - v u , where v is image distance and u is object distance. ⇒ 1 6 = - v u v = - u 6 By mirror formula, 1 f = 1 v + 1 u 1 f = - 6 u + 1 u 1 f = - 5 u = 5 - 0.12 1 f = 5 0.12 f = 0 . 024 m

E M B I B E

Modern's ABC+ Of Science Physics>Chapter 4 - Reflection and Refraction>Practice Exercise 4B>Q 9

EASY

10th CBSE

IMPORTANT

Earn 100

An object $10 cm$ long is placed at $15 cm$ away from a convex mirror of focal length $10 cm$ . Find the position and size of image.

Important Questions on Reflection and Refraction

MEDIUM

10th CBSE

IMPORTANT

Modern's ABC+ Of Science Physics>Chapter 4 - Reflection and Refraction>Practice Exercise 4B>Q 10

An object is kept in front of a concave mirror of focal length

15 cm

. The image formed is three times the size of the object. Calculate the two possible distances of the object from the image.

EASY

10th CBSE

IMPORTANT

Modern's ABC+ Of Science Physics>Chapter 4 - Reflection and Refraction>Practice Exercise 4B>Q 11

A small candle

2.5 cm

in size is placed

27 cm

in front of a concave mirror of radius of curvature

36 cm

. At what distance from the mirror should a screen be placed in order to achieve a sharp image? Describe the nature and size of image.

MEDIUM

10th CBSE

IMPORTANT

Modern's ABC+ Of Science Physics>Chapter 4 - Reflection and Refraction>Practice Exercise 4B>Q 12

How far should an object be from a concave mirror of radius

0.36 m

to form a real image

\frac{1}{9}

th of its size?

MEDIUM

10th CBSE

IMPORTANT

Modern's ABC+ Of Science Physics>Chapter 4 - Reflection and Refraction>Practice Exercise 4B>Q 13

A needle

1 cm

high is placed at a distance of

0.1 m

from a convex mirror of focal length

0.05 m

. Determine the position and size of the image.

MEDIUM

10th CBSE

IMPORTANT

Modern's ABC+ Of Science Physics>Chapter 4 - Reflection and Refraction>Practice Exercise 4B>Q 14

Find the focal length of a convex spherical mirror which produces an image

\frac{1}{6}

th the size of an object located

0.12 m

from the mirror?

MEDIUM

10th CBSE

IMPORTANT

Modern's ABC+ Of Science Physics>Chapter 4 - Reflection and Refraction>Practice Exercise 4B>Q 15

The image formed by a convex mirror of focal length $0.3 m$ is a quarter of the object. What is the distance (in $m$ ) of the object from the mirror?

(Choose from the following: $0.9, - 0.9, 0.09, - 0.09$ )

MEDIUM

10th CBSE

IMPORTANT

Modern's ABC+ Of Science Physics>Chapter 4 - Reflection and Refraction>Practice Exercise 4B>Q 16

If the image formed by a spherical mirror for all positions of the object placed in front of it is always erect and diminished, what type of mirror is it? Draw a labelled ray diagram to support your answer.

EASY

10th CBSE

IMPORTANT

Modern's ABC+ Of Science Physics>Chapter 4 - Reflection and Refraction>Practice Exercise 4C>Q 1

Define refraction. Why does a ray of light bend while moving from one medium to another?