A photographer needs a lens with focal length of 0.2 m for close up shots. What is the power of the lens required ? How does a lens with higher power affect the focussing capability of a camera ?

A concave lens has a focal length of 30 cm. Find the position and magnification (m) of the image for an object placed in front of it at a distance of 30 cm. State whether the image is real or virtual ?

The least distance of distinct vision of normal eye is:

1. 25 mm
2. 25 cm
3. 2.5 cm
4. 20 mm

A magnifying glass forms :

1. a real and diminished image
2. a real and magnified image
3. a virtual and magnified image
4. a virtual and diminished image