Manu observes that the image of a candle flame placed at a distance of 30 cm from a spherical lens is formed on a screen placed on the other side of the lens at a distance of 60 cm from the optical centre of the lens. Few questions came to her mind.
1. What is the type of the lens?
a. Convex lens
b. Concave lens
c. Bifocal lens
d. Plane lens
2. What is the focal length of the lens?
a. 10 cm
b. 15 cm
c. 20 cm
d. 25 cm
3. If the height of the flame is 3 cm, find the height of its image.
a. -1 cm
b. -2 cm
c. -6 cm
d. None of these
4. What is the magnification of convex lens?
5. Focal length of convex lens is