Question

An object is placed 20 cm in front of a concave mirror of focal length 15cm. Find the image position and magnification.​

Answer 1

Answer: image distance =60cm

magnification= -3

Explanation: given : object distance(u)= 20cm

focal length(f)= 15cm

image distance =?

finding the position of the image:

formula: 1/f=1/u+1/v

putting values in formula:

1/15= 1/20 + 1/v

1/v = 1/15 - 1/20

1/v=1/60

v=60cm

finding magnification:

formula: m= -v/u

m=-60/20

m= - 3