Physics Quiz: Trivia Questions On Wave Optics!

15 Questions | Total Attempts: 511  Settings  .

• 1.
For sustained interference, we need two sources which emit radiations:
• A.

Of the same intensity

• B.

Of the same amplitude

• C.

Having a constant phase difference

• D.

None of these

• 2.
Two beams of light having intensities I and 4I interfere to produce a fringe pattern on a screen. The phase difference between the beams is π/2, at a point A and π at a point B. The difference between the resultant intensities at A and B is:
• A.

2I

• B.

4I

• C.

5I

• D.

7I

• 3.
n identical waves each of intensity Io interfere each other. The ratio of maximum intensities if interference is coherent and incoherent is:
• A.

N

• B.

N2

• C.

N3

• D.

1/n2

• 4.
The initial shape of the wavefront of the beam is:
• A.

Concave

• B.

Convex near the axis and concave near the periphery

• C.

Planar

• D.

Convex

• 5.
Two coherent sources of intensity ratio β interfere. Then the value of
• A.
• B.
• C.
• D.
• 6.
The fringe width β of a diffraction pattern and the slit width d are related as:
• A.

βαd

• B.
• C.
• D.
• 7.
Two periodic waves of intensities I1 and I2 pass through a region at the same time in the same direction. The sum of the maximum and minimum intensities is:
• A.
• B.
• C.
• D.
• 8.
A beam is used in young’s double slit experiment. The slit width is d. When the velocity of electron is increased, then
• A.

No interference in observed

• B.

Fringe width increases

• C.

Fringe width decreases

• D.

Fringe width remains same

• 9.
A Polaroid produces a strong beam of light which is:
• A.

Circularly polarised

• B.

Elliptically polarised

• C.

Plane polarised

• D.

Unpolarised

• 10.
The angle between pass axis of polarizer and analyzer is 45o. The percentage of polarised light passing through analyzer is:
• A.

100%

• B.

50%

• C.

25%

• D.

75%

• 11.
A phase difference of 5π corresponds to a path difference (in terms λ) of:
• A.

• B.

10λ

• C.

5λ/2

• D.

• 12.
Two coherent monochromatic light beams of intensities I and 4I are superposed. The maximum and minimum possible intensities in the resulting beam are:
• A.

5I and I

• B.

9I and I

• C.

5I and 3I

• D.

9I and 3I

• 13.
What happens if one of the slits, say S1, in Young’s double slit experiment is covered with a glass plate which absorbs half the intensity of light from it?
• A.

The bright fringes become less bright and dark fringes have a finite light intensity

• B.

The bright fringes become brighter and dark fringes become darker

• C.

The fringe width decreases

• D.

No fringes will be observed

• 14.
In a double slit experiment, the distance between the slits is d. The screen is at a distance D from the slits. If a bright fringe is formed opposite of one of the slits, find its order:
• A.
• B.
• C.
• D.
• 15.
Two coherent monochromatic light sources are located at two vertices of an equilateral triangle. If the intensity due to each of the sources independently is 1Wm-2 at the third vertex, the resultant intensity due to both the sources at that point (i.e., at the third vertex) is:
• A.

Zero

• B.
• C.

2

• D.

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