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?**

a. -1

b. -2

c. -3

d. -4

**5. Focal length of convex lens is**

a. Negative

b. Positive