Question

Assume that the sun rotates about an axis through its centre and perpendicular to the plane of rotation of the earth about the sun. The appearance of the sun, from any one point on the earth, is shown. Light belonging to a particular spectral line, as received from the points A, B, C and D on the edge of the sun, are analyzed.

(a) Light from all four points have the same wavelength. 

(b) Light from C has greater wavelength than the light from D. 

(c) Light from D has greater wavelength than the light from C. 

(d) Light from A has the same wavelength as the light from B.

Answer 1

Correct Answer is: (c, d)

From the figure, C moves towards the earth and D moves away from the earth. The light from C will decrease in wavelength and the light from D will increase in wavelength.