Sustained interference fringes can be formed by the superposition of which of the following light waves?
A. $E = E_0 \sin(kx - \omega t)$
B. $E = E_0 \sin(2kx - 2\omega t)$
C. $E = E_0 \cos(kx - \omega t + \dfrac{\pi}{4})$
D. $E = E_0 \sin(kx - 3\omega t)$
Choose the correct answer from the options given below.

Question

Sustained interference fringes can be formed by the superposition of which of the following light waves?
A.

E = E_0 \sin(kx - \omega t)

B.

E = E_0 \sin(2kx - 2\omega t)

C.

E = E_0 \cos(kx - \omega t + \dfrac{\pi}{4})

D.

E = E_0 \sin(kx - 3\omega t)

Choose the correct answer from the options given below.

Quantrex Academy · Accepted Answer

Correct answer: C. A and C

For sustained interference fringes, the superposing light waves must be coherent.

Coherent waves must have the same frequency (or angular frequency

\omega

) and a constant phase difference.

From the given equations:
Angular frequency of wave A is

\omega

.
Angular frequency of wave B is

2\omega

.
Angular frequency of wave C is

\omega

.
Angular frequency of wave D is

3\omega

.

Waves A and C have the same angular frequency

\omega

.

Therefore, the superposition of waves A and C will form sustained interference fringes.

Answer: A and C

Sustained interference fringes can be formed by the superposition...