Question

if the light from the sun subtend an angle Q at the pole of a concave mirror of focal length f where will it converts also find the diameter of the image draw the necessary ray diagram ​

Answer 1

Answer:

AB= Ds is diameter of sun. The sun being at infinity , the image will be formed at focus F. The diameter of image is Di.Angle Q is small. Therefore, object distance, u= Ds/<Q.

Di/Ds= magnification = v/u=f/u=R/2u.

Therefore, Di=(R/2u)Ds=(R/2Ds/Q))Ds.= (1/2)QxR OR

Di=(1/2)Q(2f)=Qxf

Explanation: