Question

an object is placed 30 cm distance from the concave mirror and image formed at 45cm from the pole find the focal length of the mirror and mention the characteristics of image formed​

Answer 1

Explanation:

Here ,

object distance,u= -30cm

image distance,v= 45cm

By mirror formula

1/u + 1/v = 1/f

1/-30 +1/45 =1/f

-30+45=f

f=15cm

Answer 2

Answer:18

Explanation:

Given: u(object distance)=30cm

v(image distance)=45cm

To find: focal length (f)=?

According to mirror formula

1/f=1/u+1/v

1/f=-1/30-1/45

1/f=-5/90

1/f=-1/18

f=-18

Therefore, focal length = 18

And characteristics of image is real,inverted, magnified

Hope this helps you

(^_^)