In total internal reflection when the angle of incidence is equal to the critical angle for the pair of media in contact, what will be angle of refraction?

Two similar thin equi-convex lenses, of focal length f each, are kept coaxially in contact with each other such that the focal length of the combination is $F_1$. When the space between the two lenses is filled with glycerin which has the same refractive index as that of glass ($\mu =1.5$), then the equivalent focal length is $F_2$. The ratio $F_1:F_2$ will be:

Assertion: For observing traffic at our back, we prefer to use a convex mirror.

Reason: A convex mirror has a much larger field of view than a plane mirror or a concave mirror.

A biconvex lens has power P. It is cut into two symmetrical halves by a plane containing the principal axis. The power of one part will be :

A double convex lens has a focal length of 25 cm. The radius of curvature of one of the surfaces is double of the other. Find the radii if the refractive index of the material of the lens is 1.5.

A car is moving on a straight road at a speed of 50 km/h and a truck is ahead of the car and having a large plane mirror fixed vertically on the back of the truck. Truck is running at a speed of 70 km/h. For a stationary observer standing between car and truck. What is the speed of the image of the car in the mirror?

Two plane mirrors should be placed at what angle so that the incident ray and final reflected ray are antiparallel?

The field of view is maximum for

An object is placed in front of a concave mirror. The distance of the object from the focus is 10 cm and the distance of the image from the focus is 40 cm, then the focal length mirror is :

A fish at a depth y inside the water is seeing a bird. The bird is at a height x above the water level. Refractive index of water is $\mu$, then the apparent distance of the bird as seen by the fish is :

If the critical angle for a liquid A is 60$°$ and critical angle for the liquid B is 45$°$, then the critical angle for a ray traveling from A to B will be:

A convex lens made of 5 different transparent materials is used to make an image of an object placed in front of it. The number of images formed will be :

If the plane surface of a planoconvex lens is silvered, then it will behave as :

Chromatic aberration of a lens can be corrected by

A small air bubble is at the centre of a glass sphere of radii 5 cm. When it is viewed from outside what will be the position of the image?

Refractive index of glass is 1.5

The refractive indices of a prism for red, yellow and violet colours are 1.52, 1.57 and 1.62 respectively, then the dispersive power of the material of prism will be:

The magnification of a compound microscope for the final image at least distance of distinct vision is 90. The magnification of the objective lens is 15. The value of the focal length of the eyepiece will be

A terrestrial telescope is made by introducing an inverting lens of focal length $f_i$. The focal length of objective and eyepiece are $f_o and f_e$. Then the length of the telescope for normal adjustment is

The reflected light wave and incident light wave differ each other by a phase angle of ${180}^0$, when

A small source of light is 2 m below the surface of a liquid of refractive index $\frac{5}{3}$. In order to block all the light coming out of the liquid surface, the minimum diameter of the displaced on the surface of the liquid is:

A glass slab is placed with the right angle prism as shown in the figure. The possible value of $\theta$ such that light incident normally on the prism does not pass through the glass slab is:

A concave lens forms the image of an object such that the distance between the object and image is 10 cm. If magnification of the image is $\frac{1}{4}$. The focal length of the lens is

When an object is placed at 10 cm and 30 cm from a convex lens images obtained are of the same magnitude of magnification. The focal length of the lens maybe:

To increase the magnifying power of a telescope:

A ray of light is incident on a prism of angle A and refractive index $\mu$ will not emerge out of prism for any angle of incidence, if

What should be the maximum angle of acceptance at the air core interface of an optical fiber, if $n_1 and n_2$ are the refractive indices of the core and the cladding respectively?

The focal length of a glass $\left(\mu =1.5\right)$ lens in air is 20 cm. If it is dipped in water $\left(\mu =\frac{4}{3}\right)$, its focal length in water will be:

Two positions of the convex lens for which the image of the object is formed on the same screen are 40 cm and 80 cm from the object. The focal length of the lens is

When a concave mirror of focal length f is immersed in water, its focal length becomes f', then:

A person cannot see objects clearly that are closer than 2 m and farther than 4 m. To correct the eye vision, the person will use: