Question

An object is kept at a distance of 5m in front of a spherical mirror, which forms its erect image at a distance of 2m from the mirror. What is the magnification? Is the mirror concave or convex?​

Answer 1

Given:-

An object is kept at a distance of 5m in front of a spherical mirror, which forms its erect image at a distance of 2m from the mirror

Which Means

• Object Distance(u)= 5cm
• Image Distance(v)=2 m
• Image Formed is Erect.

To Find:-

• Magnification of the mirror(m)
• Mirror is Concave or Convex.

Solution:-

According to the Question

Image Formed if Erect.

Which means the image is Virtual

Then we use Magnification Formula

• $m = \frac{ - v}{u}$

So, we will Substitute the Value in this equation

$= > m = \frac{ - 2}{ - 5}$

$= > m = \frac{2}{5}$

$= > m = 4$

$\therefore the \: magnification \: of \: the \: mirror \: is \: 4cm$

Which is Positive

So, The Mirror is Convex

Answer 2

Given:

Object distance, u = 5 m

Image distance, v = 2 m

Image formed is erect.

To Find :

Magnification, m

Solution :

According to the Question

The mirror formed erect image. It means that image formed is virtual. using magnification formula

m = -v/u

Where,

m denote magnification

v denote image distance

u denote object distance

Substitute the value we get

= m= -2/-5

= m = 2/5

= m = +0.4

Hence, the magnification the mirror is 0.4.

Here, the magnification is positive. So the mirror is convex.