Question

An object at a distance of 30 cm from a concave mirror gets its image at the same point. The focal length of the mirror is
1. -30 cm
2.-15cm
3.+30cm
4.+15cm​

Answer 1

Explanation:

Answer:

Object distance(u)=-30cm

Image distance(v)=-30cm

Focel length(f)=?

From mirror equation

1/f=1/u + 1/v

1/f=(- 1/30)+(-1/30)

1/f=-1/15

f=-15cm

Therefore, focel length=-15cm

So, its a concave mirror where obect is placed at centre of curvature.

Explanation:

For any spherical mirror the object distance is always negetive since the object is placed on the left from the pole.

I hope it will help you ✌️

Answer 2

Answer:

bro is vale question ka ans to h -15cm

ans glass slab vaale ka tha 90°