Define resolving power of an astronomical refracting telescope and write expression for it in normal adjustment.Assume that light of wave length 6000Å is coming from a star, what is the limit of resolution of a telescope whose objective has a diameter of 2.54m?

Explanation

Resolving power (R.P) of astronomical telescope is its ability of form separate images of two neighboring
astronomical objects like stars etc.
`"R.P" = (1)/(d theta) = (D)/(1.22lambda)` where D is diameter of objective lens and `lambda` is wave length of light used.
`D = 100"inch" = 2.54 xx 100"cm" = 254"cm"`
= 2.54m
`lambda = 6000 Å`
Limit of resolution `d theta = (1.22 lambda)/(D)`
`= (1.22 xx 6000 xx 10^(-10)m)/(254 xx 10 ^(-2)m)`
` = 2.9 xx 10^(-10)`