Question

Assertion: Mirror formula can be applied to a plane mirror.
Reason: A plane mirror is a spherical mirror of infinite focal length

Answer 1

Answer:

Assertion is true but reason is false.

Explanation:

1. Why is the assertion true?

For plane mirrors, we can apply the usual mirror formula.

=)  1/v + 1/u = 1/f = 2/R

where u is the object distance, v is the image distance, f is the focal length and R is the radius of curvature. From this, when object is placed in front of the mirror, image will be formed at the back of the mirror.

2. Why is the reason false?

Firstly, a plane mirror is not a spherical mirror.

And secondly, the reason does not provide a genuine reason for the assertion.

Hope it helps you. Please mark as brainliest.

Answer 2

Answer:

Both an assertion and a reason is true.

Explanation:

A mirror with flat reflective surface is called plane mirror.

Mirror formula is given as,

$\frac{1}{f } = \frac{1}{u} + \frac{1}{v}$

where

f= focal length

u= Object distance

v= Image distance

• For a plane mirror, focal length is infinity. Hence, putting thee value of f in above formula,

0=1/u+1/v

1/v=-1/u

v=u

Here, the object distance becomes equal to image distance which proves mirror formula can be applied to a plane mirror.

• A reason is true only if the plane mirror is of infinite radius of curvature and the focal length i.e R=f=infinity.

Hence, for above condition, a plane mirror can be a spberical mirror with infinite focal length.