A telescope, whose objective lens has an apertune of 1 mm for the wavelength of light 500 A, then limiting resolving power of the telescope is

Options

A. ` 2.1 xx 10^(-5)` rad
B. `4.1 xx 10^(-5)` rad
C. `5.1 xx 10^(-5)` rad
D. `6.1 xx 10^(-5)` rad

Answer

D

Explanation

According to the question given that
Aperture of objective lens
`(a) = 1mm = 1 xx10^(-3)m`
Wavelength of light
` (lambda) = 500 Å = 500 xx 10^(-10)m`
`therefore` Limiting resolving power of telescope,
`dtheta = (1.22lambda)/(a) = (1.22 xx 500 xx 10^(-10))/(1xx 10^(-3))`
` = 6 .1 xx 10^(-5)` rad