A concave mirror of radius of curvature 20 cm forms image of the sun. The diameter of the sun subtends an angle `1^(@)` on the earth. Then the diameter of the image is (in cm) :

A mirror produces on a screen an image of the sun 2cm in diameter. If the sun's disc subtends an angle 0.1 radian on the surface of the earth, then the radius of curvature of the mirror is

A concave mirror forms an image of sun at a distance of 12 cm from it .

A concave mirror forms an image of the sun at a distance of 12 cm from it.

A concave mirror forms an image of the sun at a distance of 12 cm from it.

A small astronomical telescope has an objective of focal length 50 cm and an eyepiece of focal length 5 cm . It is focussed at the sun and the final image is formed at a distance of 25 cm from the eyepiece . If the diameter of the sun subtends an angle of 32' at the centre of the objective calculate the angular magnification of the instrument and the actual size of the image.

Image formed by a concave mirror radius of curvature 40 cm is half the size of the object. Then distance of object and its image from the mirror will be -