The objective of an astronomical telescope has a diameter of 150 mm and a focal length of 4.00 m.The eyepiece has a focal length of 25.00 mm. Calculate the magnifying and resolving power of telescope.(λ=6000 A for yellow colour).
the magnification is given as
m = fo / fe
here
fo = focal length of objective = 4m
fe = focal length of eyepiece = 25mm = 0.025m
so,
m = 4 / 0.025
thus, we have
magnification
m = 160
.
the resolving power is given as
R = 1.22λ / D
here
λ = wavelength of light = 6000 A = 6000 x 10-10 m
D = diameter of the objective = 150mm = 1.5m
so,
R = (1.22 x 6000 x 10-10) / 1.5
thus, we have
resolving power
R = 4800 A