Rays of light from Sun falls on a biconvex lens of focal length f and the circular image of Sun of radius r is formed on the focal plane of the lens. Then

intensity of image increases if f is increased

area of image is \[\pi {{r}^{2}}\] and area is directly proportional of

area of image is \[\pi {{r}^{2}}\] and area is directly proportional to \[{{f}^{2}}\]

if lower half of the lens is covered with black paper area will become half

Rays of light from Sun falls on a biconvex lens of focal length f and

1.	Rays of light from Sun falls on a biconvex lens of focal length f and the circular image of Sun of radius r is formed on the focal plane of the lens. Then
A.	area of image is \[\pi {{r}^{2}}\] and area is directly proportional of
B.	area of image is \[\pi {{r}^{2}}\] and area is directly proportional to \[{{f}^{2}}\]
C.	intensity of image increases if f is increased
D.	if lower half of the lens is covered with black paper area will become half
Answer» C. intensity of image increases if f is increased