Wave Optics

Which one of the following correctly distinguishes interference from diffraction?

1. Interference is due to one coherent source, while diffraction is due to two coherent sources.
2. Interference produces equally spaced fringes of nearly equal intensity, whereas diffraction has a broad central maximum with weaker secondary maxima.
3. Diffraction occurs only with white light.
4. Interference cannot occur with monochromatic light.

According to Malus' law, if plane-polarized light passes through an analyser whose transmission axis makes an angle of 60° with the direction of polarization, the transmitted intensity becomes:

1. I
2. I/2
3. I/4
4. Zero

In Young's double-slit experiment, one of the slits is covered. The screen will show:

1. An interference pattern
2. A diffraction pattern due to a single slit
3. Uniform darkness
4. Two bright bands only

The first minimum in a single-slit diffraction pattern is obtained when:

1. a sin θ = λ/2
2. a sin θ = λ
3. a sin θ = 2λ
4. a sin θ = 3λ/2

In a single-slit diffraction experiment, monochromatic light of wavelength 500 nm falls on a slit of width 0.20 mm. The screen is placed 2 m away from the slit. The angular width of the central maximum is closest to:

1. 0.14°
2. 0.29°
3. 0.57°
4. 1.43°

According to Brewster's law, the tangent of the polarizing angle is equal to:

1. Wavelength of light
2. Refractive index of the medium
3. Speed of light
4. Intensity of light

Which of the following phenomena can occur only in transverse waves?

1. Reflection
2. Refraction
3. Polarization
4. Diffraction

The phenomenon that provides convincing evidence for the wave nature of light is:

1. Reflection
2. Refraction
3. Diffraction
4. Photoelectric effect

In Young's double-slit experiment, the distance between the slits is doubled while the wavelength and screen distance remain unchanged. The fringe width will:

1. Become double
2. Become half
3. Remain unchanged
4. Become four times

According to Huygens' principle, every point on a wavefront acts as:

1. A source of light of different frequency
2. A source of secondary wavelets
3. A reflecting surface
4. A stationary point

In Young's double-slit experiment, if the wavelength of light is doubled while all other parameters remain unchanged, the fringe width becomes:

1. Half
2. Unchanged
3. Double
4. Four times

The central fringe in Young's double-slit experiment is always:

1. Dark
2. Bright
3. Alternately bright and dark
4. Invisible

Two coherent sources produce waves of the same frequency. Their phase difference remains constant with time. Such sources are called coherent because they have:

1. Same amplitude only
2. Same wavelength but different frequency
3. Constant phase difference
4. Equal intensity only

In Young's double-slit experiment, the path difference between light coming from the two slits at a point on the screen is equal to one wavelength. The point corresponds to:

1. Central bright fringe
2. First bright fringe
3. First dark fringe
4. Second dark fringe

In Young's double-slit experiment, monochromatic light of wavelength 600 nm falls on two slits separated by 0.30 mm. The screen is placed 1.5 m away from the slits. The fringe width is:

1. 2 mm
2. 3 mm
3. 4 mm
4. 5 mm