Physics - Geometrical Optics Question with Solution | TestHub

The magnifying power of a telescope is defined as the ratio of the angle subtended by the image at the eye to the angle subtended by the object at the unaided eye.

$m=\frac{\beta }{\alpha }=20$

This means the angle subtended by the image is $20$ times the angle subtended by the actual object. For a distant object, the angular size is inversely proportional to its distance from the observer ($\theta \approx \frac{h}{d}$).

Since the telescope increases the angular size by a factor of $20$ without changing the actual linear height of the tree, the brain interprets this increased angular size as the object being at $\frac{1}{20}$th of its original distance.

Therefore, the tree appears $20$ times nearer to the observer.

Answer: $20$ times nearer.