Introduction to YDSE

Q.

If the source of light used in Young’s double-slit experiment is changed from red to violet:

1. the fringes will become brighter.

2. consecutive fringe lines will come closer.

3. the central bright fringe will become a dark fringe.

4. the intensity of minima will increase.

Q. Interference is possible in

1. light waves only
2. sound waves only
3. both light and sound waves
4. neither light nor sound waves

Q.

The similarity between the sound waves and light waves is

[KCET 1994]

1. Both are electromagnetic waves

2. Both are longitudinal waves

3. They can produce interference

4. Both have the same speed in a medium

Q.

A double slit interference experiment is carried out in air and the entire arrangement is dipped in water. The fringe width

1. increases

2. decreases

3. remains unchanged

4. fringe pattern disappears

Q. two waves of same frequency and of intensity $I_0$ and $9I_0$ produces interference. If at a certain point the resultant intensity is $7I_0$ then the minimum phase difference between the two sound waves will be

1. ${90}^0$
2. ${150}^0$
3. ${120}^0$
4. ${100}^0$

Q.

Two coherent light sources each of wavelength $\lambda$ are separated by a distance $3\lambda$. The total number of minima formed on line AB which runs from $-\infty$ to $+\infty$ is:

1. 2

2. 4

3. 6

4. 8

Q. In young's double-slit experiment the intensity of light at a point on the screen where the path difference is $\lambda$ is $I$, $\lambda$ being the wavelength of light used. The intensity at a point where the path difference is $\frac{\lambda }{4}$ will be

1. $I$
2. zero
3. $\frac{I}{4}$
4. $\frac{I}{2}$

Q. The frequencies of X-rays, $\gamma$ rays and Ultra violet rays are respectively incident on a metal, having work function is $0.5eV$. The ratio of maximum speed of emtted electrons is

1. $p<q,q>r$
2. $p>q,q>r$
3. $p<q,q<r$
4. $p>q,q<r$

Q. Two coherent light sources each of wavelength $\lambda$ are separated by a distance $3\lambda$. The total number of minima formed on line AB which runs from $-\infty$ to $+\infty$ is:

1. 2
2. 4
3. 6
4. 8

Q. The interference of light was first demonstrated experimentally by

1. Sir Isaac Newton
2. Michelson
3. Fraunhoffer
4. Thomas Young

Q. Interference occurs in which of the following waves?

1. Transverse
2. Electromagnetic
3. Longitudinal
4. All of these

Q. Two coherent light sources, each of wavelength $\lambda$, are separated by a distance of $3\lambda$. The maximum number of minima formed on the line $\text{AB}$, which runs from $-\infty$ to $+\infty$, is

1. $2$
2. $4$
3. $6$
4. $8$

Q.

A parallel beam of light of wavelength 560 nm falls on a thin film of oil (refractive index = 1.4). What shoul be the minimum thickness of the film so that it strongly reflects the light?

Q.

In Young's double slit experiment, if one of the slit is closed fully, what will be visible on the screen?

1. A slit-shaped bright spot

2. A YDSE interference pattern

3. A diffraction pattern

4. Nothing will be visible

Q. Assertion(A): To transmit low frequency audio signals over long distances, the audio signals are superimposed on a high frequency carrier signal.
Reason(R): Low frequency audio signals cannot be transmitted directly over long distances.

1. A and R are true but R is not correct explanation of A
2. A is false but R is true.
3. A and R are true and R is the correct explanation of A
4. A is true but R is false

Q. A source of sound moves towards a listener with a velocity equal to that of sound. If the source emits n waves per second, then the listener moving away from the source with the same velocity receives

1. n waves per sec
2. zero waves per sec
3. 2n waves per sec
4. $\frac{n}{2}$

Q. Are $R_1,R_2,R_3,R_4$ and $R_5$ nearly in phase

1. yes
2. no
3. maintain a constant phase
4. insufficient data to reply

Q. Two light sources are coherent when:

1. their wavelength are equal
2. Their amplitudes are equal
3. Only their frequency are equal
4. Time frequency are equal and their phase

Q. Sound waves in air cannot be polarised because they are

1. progressive
2. stationary
3. longitudinal
4. transverse

Q. Assertion :Two point coherent sources of light $S_1$ and $S_2$ are placed on a line as shown in figure. $P$ and $Q$ are two points on that line. If at point $P$ maximum intensity is observed, then maximum intensity should also be observed at $Q$. Reason: In the figure, the distance $|S_{1}P-S_{2}P|$ is equal to distance $|S_{1}Q-S_{2}Q|$

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Assertion is incorrect but Reason is correct

Q.

1. Refraction
2. Reflection
3. Polarization
4. Interference
5. Intensity

Q. what is basic function of demodulation of waves ?

Q. Assertion: If a person wants to observe sharp and clear fringes of good contrast, then, interference experiment is preferable compared to diffraction

Reason: In diffraction, intensity after the central maximum decreases rapidly, so fringe pattern become blurred.

1. The assertion is true, but the reason is false
2. Both the assertion and reason are false
3. Both Assertion and reason are true, but the reason is not the correct explanation of the assertion.
4. Both Assertion and reason are true, and the reason is the correct explanation of the assertion.