Question

At what distance from a concave mirror of focal length 10cm should an object is placed if the image is formed at a distance of 20 cm from the mirror

Answer 1

Answer:

20cm

explanation ,

here ,f=10cm

v=20cm

according to Mirror formula ,

1/v+1/u=1/f

putting this value , we get ,

1/20+1/u=1/10

• 1/u=1/10-1/20
• =2-1/20
• =1/20
• u=20cm
• if an object is placed at a distance of 20cm from the mirror then image distance will be 20cm.