Wave Optics

In single slit experiment, the width of the slit is reduced. Then, the line width of the principal maxima

• decreases but becomes less bright

• increases but becomes less bright

• decreases but becomes more bright

• increases but becomes more bright

If the two slits in Young's double slit experiment are of unequal width, then

• the dark fringes are not perfectly dark

• the bright fringes will have unequal spacing

• the bright fringes will have unequal brightness

• the fringes do not appear

The phenomenon of polarizaton shows that light has...... nature

• dual

• particle

• transverse

• longitudinal

Which of the following phenomena suppor tthe wave theory of light ? 

1. Scattering
2. Interference
3. Diffraction
4. Velocity of light in a denser medium is less than the velocity of light in the rare medium.

• 1, 2 and 3

• 1, 2 and 4

• 2, 3 and 4

• 1, 3 and 4

White light reflected from a soap film (Refractive Index = 1.5) has a maxima at 600 nm and a minima at 450 nm with no minimum in between. Then the thickness of the film is

• 1

• 2

• 3

• 4

λ₁ and λ₂ are used to illuminate the slits. β₁ and β₂ are the corresponding fringe widths. The wavelength λ₁ can produce photoelectric effect when incident on a metal. But the wavelength λ₂ cannot produce photoelectric effect. The correct relation between β₁ and β₂ is

• β₁ < β₂

• β₁ = β₂

• β₁ > β₂

• β₁ ≥ β₂

A fringe width of a certain interference pattern is β = 0.002 cm. What is the distance of 5th dark fringe from centre ?

• 1 × 10^-2 cm

• 11 × 10^-2 cm

• 9 × 10^-3 cm

• 3.28 × 10⁶ cm

A polarized light of intensity I₀ is passed through another polarizer whose pass axis makes an angle of 60° with the pass axis of the former. What is the intensity of emergent polarized light from second polarizer ?

• I = I₀

• I = I₀/6

• I = I₀/5

• I₀/4

In a Young's double slit experiment, the slit separation is 0.5 mm and the screen is 0.5 m from the slits. For a monochromatic light of wavelength 500 nm, the distance of 3rd maxima from 2nd minima on the other side of central maxima is

• 22.5 mm

• 2.75 mm

• 2.25 mm

• 2.5 mm

The polarising angle of glass is 57°. A ray of light which is incident at this angle will have an angle of refraction as

• 43°

• 25°

• 38°

• 33°