A point object is situated at a distance of 30 cm from a convex mirror having a focal length of 30 cm . The image will be formed at

Correct answer: C. 15 cm behind the mirror Using the mirror formula, (1)/(v) + (1)/(u) = (1)/(f) For a convex mirror, focal length f = +30 cm . Object distance u = -30 cm . Substituting the values, we get: (1)/(v) + (1)/(-30) = (1)/(30) (1)/(v) = (1)/(30) + (1)/(30) = (2)/(30) = (1)/(15) v = +15 cm The positive sign indicates that the image is formed 15 cm behind the mirror.

Concepts Of Physics MCQ Edition [Volume 1]

Exam: Concepts Of Physics MCQ Edition [Volume 1]
Subject: Physics
Chapter: Geometrical Optics

Concepts Of Physics MCQ Edition [Volume 1] · Physics · Geometrical Optics

A point object is situated at a distance of 30 cm from a convex...

A point object is situated at a distance of

30 \text{ cm}

from a convex mirror having a focal length of

30 \text{ cm}

. The image will be formed at

Options

Ainfinity
Bfocus
C $15 \text{ cm}$ behind the mirror
Dpole

Correct answer

C. $15 \text{ cm}$ behind the mirror

Step-by-step solution

Using the mirror formula,

\dfrac{1}{v} + \dfrac{1}{u} = \dfrac{1}{f}

For a convex mirror, focal length

f = +30 \text{ cm}

.

Object distance

u = -30 \text{ cm}

.

Substituting the values, we get:

\dfrac{1}{v} + \dfrac{1}{-30} = \dfrac{1}{30}

\dfrac{1}{v} = \dfrac{1}{30} + \dfrac{1}{30} = \dfrac{2}{30} = \dfrac{1}{15}

v = +15 \text{ cm}

The positive sign indicates that the image is formed

15 \text{ cm}

behind the mirror.

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