Ray optics practice · Mixed difficulty

The cladding material of optical fibre has refractive index

Assertion (A) The relation among ${u}, {v}$ and ${f}$ for the spherical mirror is valid only for mirrors whose sizes are very small compared to their radii of curvature.

Reason (R) The laws of reflection are strictly valid for plane surfaces but not for large spherical surfaces.

The image produced by a concave mirror is one quarter the size of object. If the object is moved $5 \mathrm{~cm}$ closer to the mirror, the image will only be half the size of the object. The focal length of mirror is:

A person sees his virtual image by holding a mirror very close to the face. When he moves the mirror away from his face, the image becomes inverted. What type of mirror he is using?

A person can see upto distance $x$, wants to see distance $y(y>x)$ then power of the lens should be:

Assertion: The focal length of lens does not change when red light is replaced by blue light.

Reason: The focal length of lens does not depends upon colour of the light used.

A plane mirror rotating at an angular velocity 4 radian/s reflects a light beam. The angular velocity of the reflected beam is

What will be the colour of sky as seen from the earth, if there were no atmosphere

The focal length of a concave mirror is $50 \mathrm{~cm}$. Where an object be placed so that its image is two times and inverted

If there had been one eye of the man, then

What causes chromatic aberration?

Which of the prism is used to see infrared spectrum of light

A plane glass slab is kept over various coloured letters; the letter which appears maximum raised is

Statement-A: Minimum deviation for a given prism does not depend on the refractive index $\mu$ of the prism.

Statement-B: Deviation by a prism is given by $\delta=\left(i_1+i_2-A\right)$ and does not have the term $\mu$.

Refractive indices of water and glass are $\frac{4}{3}$ and $\frac{3}{2}$ respecitvely. A ray of light travelling in water is incident on the water glass interface at $30^{\circ}$. The angle of refraction is :

A small source of light is to be suspended directly above the centre of a circular table of radius $R$. What should be the height of the light source above the table so that the intensity of light is maximum at the edges of the table compared to any other height of the source

A lens forms the image of sun on a screen $30 \mathrm{~cm}$ away. How far (in decimeter) from the lens should a second lens of focal length $30 \mathrm{~cm}$ placed so that the screen has to be moved $8 \mathrm{~cm}$ towards the first lens for the new image to be in focus?

A passenger in an aeroplane shall

The minimum distance between the object and its real image for concave mirror of focal length $f$ is

If white light traveling in air incidents over glass and undergoes refraction then which colour light deviates maximum -

An object is placed 21 cm in front of a concave mirror of radius of curvature 10 cm. A glass slab of thickness 3 cm and refractive index 3/2 is then placed close to the mirror the space between the object and the mirror. Distance of the near surface of the slab from the mirror is 1 cm. Find the position of the final image formed:-

A plane mirror reflects a beam of light to from a real image. The incident beam is :

Optical fibres are related with

Myopia is due to

In a compound microscope, if the objective produces an image ${I_0}$ and the eye piece produces an image ${I_e}$, then

Myopia can be corrected by using the

When light travels from one medium to the other of which the refractive index is different, then which of the following will change

Statement I : Endoscopy involves use of optical fibres to study intemal organs.

Statement II : Optical fibres are based on the phenomenon of total internal reflection.

A man can see clearly upto $3 \mathrm{~m}$. To see upto $12 \mathrm{~m}$, he must use a lens of

Total internal reflection can take place only if