Question

At what distance the concave mirror of focal length of 10cm forms an image twice the size of the object

Answer 1

Answer:

either 5 cm or 15 cm

m=OI=u−v=±2

Case-1

u=2v

u1+v1=f1

u1+2u1=10−1

∴u=−15cm

case-2

u=−2v

u1−2u1=10−1⇒2u2−1=10−1

∴u=−5cm

∴u=−5 or −15.