Question 1

The maximum intensity using coherent sources compared to the maximum intensity using random sources for sources of equal strength is that the maximum in the coherent case is

Accepted Answer

In coherent sources, the maximum intensity is due to constructive interference, which results in the intensities adding up to four times the intensity of a single source. In incoherent sources, intensities simply add up, resulting in double the intensity of a single source. Therefore, the maximum intensity in the coherent case is double that of the incoherent case.

Question 2

Which one of the following experiments is the justification for the wave theory of light?

Accepted Answer

Young's double slit experiment demonstrated the interference pattern of light, which could only be explained by the wave theory of light.

Question 3

At the second maxima on either side of the central bright spot in a double-slit experiment, light from

Accepted Answer

In a double-slit experiment, the condition for the second maxima is that the path difference between the two waves should be two wavelengths.

Question 4

Two light sources are said to be coherent if they

Accepted Answer

Coherent light sources must have the same frequency and maintain a constant phase difference to produce stable interference patterns.

Question 5

Sources are coherent if

Accepted Answer

Coherent sources have a constant phase difference, which allows them to produce a stable interference pattern.

Question 6

If in a double-slit experiment the wavelength of light is increased, which of the following happens to the interference pattern shown on the screen?

Accepted Answer

Increasing the wavelength of light in a double-slit experiment causes the interference fringes (maxima) to spread out, making them further apart. This is because the fringe spacing is directly proportional to the wavelength.

Question 7

When a beam of light, which is traveling in glass, strikes an air boundary, there is

Accepted Answer

The answer of When a beam of light, which is...

Question 8

If a wave from one slit of a Young's double slit experiment arrives at a point on the screen one-half wavelength behind the wave from the other slit, which is observed at that point?

Accepted Answer

A dark fringe is observed because the waves are out of phase by half a wavelength, resulting in destructive interference.

Question 9

At the first minima on either side of the central bright spot in a double-slit experiment, light from each opening arrives

Accepted Answer

At the first minima in a double-slit experiment, the light from each slit arrives 180° out of phase, causing destructive interference and resulting in a dark fringe.

Question 10

One beam of coherent light travels path P₁ in arriving at point Q and another coherent beam travels path P₂ in arriving at the same point. If these two beams are to interfere destructively, the path difference P₁ - P₂ must be equal to

Accepted Answer

For destructive interference, the path difference between two coherent beams must be an odd number of half-wavelengths, causing the waves to be out of phase.

Question 11

The colors on an oil slick are caused by reflection and

Accepted Answer

The colors on an oil slick are caused by interference, which occurs when light waves reflected from the top and bottom surfaces of the thin oil film combine, enhancing or canceling out certain wavelengths of light.

Question 12

When light in medium 1 is reflected from the surface of medium 2 with the indices of refraction of the media being n₁ and n₂ respectively, the reflected light has a phase difference of 180° if

Accepted Answer

The reflected light undergoes a phase shift of 180° when it reflects off a medium with a higher index of refraction (n₂) than the medium it is coming from (n₁).

Question 13

At the first maxima on either side of the central bright spot in a double-slit experiment, light from each opening arrives

Accepted Answer

At the first maxima on either side of the central bright spot, light from each opening arrives in phase.

Question 14

When a beam of light, which is traveling in air, is reflected by a glass surface, there is

Accepted Answer

When a beam of light traveling in air reflects off a surface with a higher refractive index, such as glass, there is a 180° phase change in the reflected beam. This is because the electric field of the reflected wave is inverted due to the change in media.

Question 15

Waves that are emitted in phase from two sources will undergo destructive interference when the paths from the sources differ by

Accepted Answer

Destructive interference occurs when waves are out of phase by an odd half-integer number of wavelengths, causing them to cancel each other out.

Question 16

Waves that are emitted in phase from two sources will undergo constructive interference when the paths from the sources differ by

Accepted Answer

Constructive interference occurs when the path difference between two waves is an integer multiple of the wavelength, leading to the waves being in phase.

Question 17

Two beams of coherent light travel different paths arriving at point P. If the maximum destructive interference is to occur at point P, what should be the phase difference between the two waves?

Accepted Answer

For destructive interference to occur, the phase difference between the two waves must be π (or an odd multiple of π). This is because the peaks of one wave will coincide with the troughs of the other wave, resulting in cancellation. Therefore, choice C is the correct answer.

Question 18

If in a double-slit experiment the slit separation is increased, which of the following happens to the interference pattern shown on the screen?

Accepted Answer

Increasing the slit separation decreases the fringe spacing, causing the minima to get closer together.

Question 19

If in a double-slit experiment the distance to the screen is increased, which of the following happens to the interference pattern shown on the screen?

Accepted Answer

Increasing the distance to the screen increases the spacing between the interference fringes, causing the maxima to get further apart.

Question 20

Two beams of coherent light travel different paths arriving at point P. If the maximum constructive interference is to occur at point P, what should be the phase difference between the two waves?

Accepted Answer

The answer of Two beams of coherent light travel different...

Quiz 34: The Wave Nature of Light; Interference