A glass sphere \(\left(\mu = \frac{3}{2}\right)\) of radius \(12~\text{cm}\) has a small mark at a distance of \(3~\text{cm}\) from its centre. Where will this mark appear when it is viewed from the side nearest to the mark along the line joining the centre and the mark?

1.	\(8~\text{cm}\) inside the sphere	2.	\(12~\text{cm}\) inside the sphere
3.	\(4~\text{cm}\) inside the sphere	4.	\(3~\text{cm}\) inside the sphere

A ray of light falls on a prism \(ABC\) \((AB= BC)\) and travels as shown in figure. The refractive index of the prism material should be greater than:

A fish is a little away below the surface of a lake. If the critical angle is \(49^{\circ},\) then the fish could see things above the water surface within an angular range of \(\theta^{\circ}\) where:

A plane mirror is placed at the bottom of a fish tank filled with water of refractive index \(\dfrac{4}{3}.\) The fish is at a height \(10~\text{cm}\) above the plane mirror. An observer \(O\) is vertically above the fish outside the water. The apparent distance between the fish and its image is:

If \(C_1,~C_2 ~\mathrm{and}~C_3\) are the critical angle of glass-air interface for red, violet and yellow color, then:

An object is placed \(20~\text{cm}\) in front of a concave mirror of a radius of curvature \(10~\text{cm}.\) The position of the image from the pole of the mirror is:
1. \(7.67~\text{cm}\)
2. \(6.67~\text{cm}\)
3. \(8.67~\text{cm}\)
4. \(9.67~\text{cm}\)