An object is placed 25 cm from a concave mirror of focal length 15 cm — JEE Physics
An object is placed 25 cm from a concave mirror of focal length 15 cm. Find the image distance.
1 Answer
VAVidaara Admin
✓ Vidaara Team
✓ Accepted
· 1mo ago
▲ 40
$$\frac{1}{v} + \frac{1}{u} = \frac{1}{f}$$
With $u = -25$ cm, $f = -15$ cm:
$$\frac{1}{v} = \frac{1}{-15} - \frac{1}{-25} = -\frac{1}{15} + \frac{1}{25} = \frac{-5+3}{75} = -\frac{2}{75}$$
$$v = -37.5 cm \Rightarrow Real, inverted image at 37.5 cm in front of mirror$$
Log in to post your own answer or join the discussion.
Discussion (2)
SJ
Does this approach generalise to the JEE Advanced version of this question?
M
For revision — the key formula used here comes up almost every year.