A telescope has an objective lens of focal length 150 cm and an eyepiece of focal length 5 cm. If a 50 m tall tower at a distance of 1 km is observed through this telescope in normal setting, the angle formed by the image of the tower is θ, then θ is close to

Question

Accepted Answer

(4) 60°. M = (fₒ)/(fₑ) = (150)/5 = 30 Tower subtends tan α = (50)/(1000) = 0.05 tan θ = M tan α = 1.5, so θ ≈ 56° Closest option: 60° → option 4

A telescope has an objective lens of focal length 150 cm and an eyepiece of focal length 5 cm. If a 50 m tall tower at a distance of 1 km is observed through this telescope in normal setting, the angle formed by the image of the tower is θ, then θ is close to

Step-by-step solution

Why the other options are wrong