Question

An object kept at 25 cm in front of a plane mirror is moved 5 more centimetres away from the mirror. How much did the distance between the object and its image increase ?

• A. 15 cm
• B. 10 cm
• C. 50 cm
• D. 60 cm

Answer 1

The correct option is B 10 cm

Distance between object and its image before the object moved was,
$D_{initial}=25cm\times 2=50cm$

Now, since the object moved 5 more centimetres away from the mirror, the new distance between the object and the mirror is 30 cm.

Therefore distance between the object and its image is,
$D_{final}=30cm\times 2=60cm$

Therefore, increased distance is equal to,
$Increase=D_{final}-D_{initial}=60-50=10cm$