Question

Q. In order to obtain a magnification of, -1.5 with a concave mirror of focal length 16 cm, the object will have to be placed at a distance :

(a) between 6 cm and 16cm.

(b) between 32 and 16 cm.

(c) between 48 and 32 cm.

(d) beyond 64cm​.

Plz guys answer this....​

Answer 1

Answer:

a) between 6 cm and 16 cm

Answer 2

given magnification m = -1.5

m = -v/u = -1.5

v = 1.5u

now

for concave mirror

1/u + 1/v = 1/f

1/u + 1/1.5u = 1/16

1/u (1 + 1/1.5) = 1/16

1/u (2.5/1.5) = 1/16

1/u (5/3) = 1/16

5/3u = 1/16

3u = 80

u = 80/3 = 26.66

thus object is to be placed beyond 26 cm which is in the interval of 32 cm and 16 cm

hence option b