Geometrical Optics

In normal adujstment, for a refracting telescope, the distance between objective and eye piece is $$30 \mathrm{~cm}$$. The focal length of the objective, when the angular magnification of the telescope is 2 , will be :

A scientist is observing a bacteria through a compound microscope. For better analysis and to improve its resolving power he should. (Select the best option)

In a reflecting telescope, a secondary mirror is used to:

Identify the physical quantity that cannot be measured using spherometer :

If two mirrors are kept at $${60^ \circ }$$ to each other, then the number of images formed by them is

To get three images of a single object, one should have two plane mirrors at an angle of

A car is fitted with a convex side-view mirror of focal length $$20$$ $$cm$$. A second car $$2.8m$$ behind the first car is overtaking the first car at a relative speed of $$15$$ $$m/s$$. The speed of the image of the second car as seen in the mirror of the first one is :

Two plane mirrors are inclined to each other such that a ray of light incident on the first mirror (M₁) and parallel to the second mirror (M₂) is finally reflected from the second mirror (M₂) parallel to the first mirror (M₁). The angle between the two mirrors will be :

The incident ray, reflected ray and the outward drawn normal are denoted by the unit vectors $$\overrightarrow a$$, $$\overrightarrow b$$ and $$\overrightarrow c$$ respectively. Then choose the correct relation for these vectors.

Car B overtakes another car A at a relative speed of 40 ms^$$-$$1. How fast will the image of car B appear to move in the mirror of focal length 10 cm fitted in car A, when the car B is 1.9 m away from the car A?