1. | \(8\) cm inside the sphere | 2. | \(12\) cm inside the sphere |
3. | \(4\) cm inside the sphere | 4. | \(3\) 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:
1. | \(4 /{3}\) | 2. | \( \sqrt{2}\) |
3. | \(1.5\) | 4. | \( \sqrt{3}\) |
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:
1. | \(\theta = 49^{\circ}\) | 2. | \(\theta = 90^{\circ}\) |
3. | \(\theta = 98^{\circ}\) | 4. | \(\theta = 24\frac{1}{2}^{\circ}\) |
1. | \(80\) cm | 2. | \(40\) cm |
3. | \(60\) cm | 4. | \(20\) cm |
1. | \(f' = f\) |
2. | \(f'<f\) |
3. | \(f'>f\) |
4. | The information is insufficient to predict |
1. | \(X+Y\) | 2. | \(\frac{X + Y}{2}\) |
3. | \(X-Y\) | 4. | \(\frac{X - Y}{2}\) |
A plane mirror is placed at the bottom of a fish tank filled with water of refractive index \(\frac{4}{3}.\) The fish is at a height \(10\) cm above the plane mirror. An observer \(O\) is vertically above the fish outside water. The apparent distance between the fish and its image is:
1. | \(15\) cm | 2. | \(30\) cm |
3. | \(35\) cm | 4. | \(45\) cm |
If \(C_1,~C_2 ~\mathrm{and}~C_3\) are the critical angle of glass-air interface for red, violet and yellow color, then:
1. | \(C_3>C_2>C_1\) | 2. | \(C_1>C_2>C_3\) |
3. | \(C_1=C_2=C_3\) | 4. | \(C_1>C_3>C_2\) |
An object is placed \(20\) cm in front of a concave mirror of a radius of curvature \(10\) cm. The position of the image from the pole of the mirror is:
1. \(7.67\) cm
2. \(6.67\) cm
3. \(8.67\) cm
4. \(9.67\) cm
1. | \(\frac{\sqrt{3}}{2} \) | 2. | \(1.5 \) |
3. | \(1.732 \) | 4. | \( 2\) |