Question

1. A concave mirror has a focal length of 20cm.Where in front of the mirror an object should be placed so that an erect image is formed? ​

Answer 1

Given info :  A concave mirror has a focal length of 20cm.

To find : where in front of the mirror an object sould be placed so that an erect image is formed ?

solution : A concave mirror forms an erect image only when object is placed between the focus and pole.

see diagram, here an object AB is placed between F and pole of mirror, due to this an erect image is formed in front of the mirror and it is larger than that of object.

  therefore the object should be placed between the focus and the pole of mirror so that an erect image will be formed in front of the mirror.

Answer 2

Answer:

10cm

Explanation:

To get an erect image the object should be placed between pole and focus of the mirror