Question

How far should an object be placed from the pole of converging mirror?

Answer 1

we know that; m = -v/u

=> 1/4 = -v/u

=> u = -4v .... (1)

Now,

we also know that;

1/f = 1/v + 1/u

=> 1/20 = 1/v - 1/4v [using (1)]

=> 1/20 = (4 - 1)4v

=> 1/5 = 3/v

=> v = 15

putting the value of v in 1. we get;

u = -4*15

=> u = -60 cm

hence , object is placed 60cm from mirror.

Answer 2

Answer:

U = - 60 cm is your correct answer✔✔