Question

The diagram below shows image formation A'B' of an object AB kept between
pole (P) and Focus (F) in a spherical mirror MM'.
Identify the spherical mirror used and state the focal length of the spherical
mirror. (Do not draw the diagram.)​

Answer 1

Answer:

Here c = 17

So f would be 17/2 = 8.5

But it could be positive or negative.. To check that we will have to identify the mirror..

Here according to condition object is between pole and focus.. So only two cases could be possible

1) its concave mirror and object is placed between pole and focus

2) its convex mirror and object is placed (not infinity)

But in concave mirror you find the magnifying image.. As shown in diagram image is magnified (enlarged) .. So your mirror would be concave mirror..

And focal length would be - 8.5 cm

Answer 2

Answer:

This is a concave mirror.

We know that focal length is equal to the half of the radius of curvature.

Thus,

f = R/2

= -17/2

= -8.5 cm

Hope it helps

Best of luck.