1. | \(120^\circ\) | 2. | \(30^\circ\) |
3. | \(60^\circ\) | 4. | \(90^\circ\) |
A beam of light is incident vertically on a glass slab of thickness \(1\) cm, and refractive index \(1.5.\) A fraction \(A\) is reflected from the front surface while another fraction \(B\) enters the slab and emerges after reflection from the back surface. The time delay between them is:
1. | \(10^{-10}\) s | 2. | \(5\times 10^{-10}\) s |
3. | \(10^{-11}\) s | 4. | \(5\times 10^{-11}\) s |
An air bubble in a glass slab with a refractive index \(1.5\) (near-normal incidence) is \(5\) cm deep when viewed from one surface and \(3\) cm deep when viewed from the opposite surface. The thickness (in cm) of the slab is:
1. | \(8\) | 2. | \(10\) |
3. | \(12\) | 4. | \(16\) |
The frequency of a light wave in a material is 2×1014 Hz and the wavelength is 5000 Å. The refractive index of the material will be:
1. 1.40
2. 1.50
3. 3.00
4. 1.33
A beam of light composed of red and green rays is incident obliquely at a point on the face of a rectangular glass slab. When coming out on the opposite parallel face, the red and green rays emerge from:
1. | Two points propagating in two different parallel directions |
2. | One point propagating in two different directions through the slab |
3. | One point propagating in the same direction through the slab |
4. | Two points propagating in two different non-parallel directions |
A ray of light travelling in the air has wavelength λ, frequency n, velocity v, and intensity I. If this ray enters into water then these parameters are λ', n', v' and I' respectively. Which relation is correct?
1. λ = λ′
2. n = n′
3. v = v′
4. I = I′
A bubble in glass slab (µ = 1.5) when viewed from one side appears at 5 cm and 2 cm when viewed from the other side. Thickness of the slab is:
1. 3.75 cm
2. 3 cm
3. 10.5 cm
4. 2.5 cm