JEE Main 2017 (Online) 9th April Morning Slot | Geometrical Optics Question 162 | Physics

In an experiment a convex lens of focal length 15 cm is placed coaxially on an optical bench in front of a convex mirror at a distance of 5 cm from it. It is found that an object and its image coincide, if the object is placed at a distance of 20 cm from the lens. The focal length of the convex mirror is :

27.5 cm

20.0 cm

25.0 cm

30.5 cm

JEE Main 2017 (Online) 8th April Morning Slot

MCQ (Single Correct Answer)

-1

Let the refractive index of a denser medium with respect to a rarer medium be n₁₂ and its critical angle be θ_C . At an angle of incidence A when light is travelling from denser medium to rarer medium, a part of the light is reflected and the rest is refracted and the angle between reflected and refracted rays is 90^o. Angle A is given by :

$${1 \over {{{\cos }^{ - 1}}\left( {\sin {\theta _C}} \right)}}$$

$${1 \over {{{\tan }^{ - 1}}\left( {\sin {\theta _C}} \right)}}$$

$${\cos ^{ - 1}}\,\left( {\sin {\theta _C}} \right)$$

$${\tan ^{ - 1}}\,\left( {\sin {\theta _C}} \right)$$

JEE Main 2017 (Offline)

MCQ (Single Correct Answer)

-1

A diverging lens with magnitude of focal length 25 cm is placed at a distance of 15cm from a converging lens of magnitude of focal length 20cm. A beam of parallel light falls on the diverging lens. The final image formed is:

real and at a distance of 6 cm from the convergent lens.

real and at a distance of 40 cm from convergent lens.

virtual and at a distance of 40 cm from convergent lens.

real and at a distance of 40 cm from the divergent lens.

JEE Main 2016 (Online) 10th April Morning Slot

MCQ (Single Correct Answer)

-1

To determine refractive index of glass slab using a travelling microscope, minimum number of readings required are :

Two

Three

Four

Five