Question

An object of size 2.0 cm is placed at a distance of 20.0 cm in front of a concave mirror of focal length 10.0 cm . At what distance should a screen be placed in order to obtain a clear focussed image of the object? ​

Answer 1

Answer:

Height of the object =2 cm

U(object distance) = -15 as u is always negative

F = -10 (as it is always negative for concave miror and lens )

1/F =1/v + 1/u

-1/10 = 1/v + (-1/15)

-1/10 +1/15 =v

-3+2/30 =v

V=-30cm

Hi/Ho = - V/U

Hi /2 = -(-30/15)

Hi =-30×2÷15

Hi =-4cm (Real and inverted)