You visited us 1 times! Enjoying our articles? Unlock Full Access!

Byju's Answer

Standard XII

Physics

Interference Definition

In the shown ...

Question

In the shown figure, answer the following question.

If $p_{i}, p_{r}, p_{t}$ are powers of incident, reflected and transmitted waves and $I_{i}, I_{r}, I_{t}$ the corresponding intensities, then under what conditions $75 %$ of incident energy is transmitted?

\frac{v_{1}}{v_{2}} = \frac{1}{2}

No worries! We‘ve got your back. Try BYJU‘S free classes today!

\frac{v_{1}}{v_{2}} = \frac{1}{3}

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

\frac{v_{1}}{v_{2}} = \frac{1}{4}

No worries! We‘ve got your back. Try BYJU‘S free classes today!

\frac{v_{1}}{v_{2}} = \frac{2}{3}

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is B $\frac{v_{1}}{v_{2}} = \frac{1}{3}$
In reflected and incident wave all other factors are common, So, it is only amplitude which can change the power.
$75 %$ is transmitted. Hence, $25 %$ or $\frac{1}{4} th$ will be reflected back.
$∴ A_{r} = \frac{A_{i}}{2}$ (as power $p \propto A^{2}$ )
or $\frac{A_{i}}{A_{r}} = 2$
or $\frac{v_{1} - v_{2}}{v_{2} - v_{1}} = 2$
or $\frac{v_{1}}{v_{2}} = \frac{1}{3}$
Hence, $(B)$ is the correct answer.

Suggest Corrections

Similar questions

Q. A travelling wave is partly reflected and partly transmitted from a rigid boundary. Let

a_{i}, a_{r}

and

a_{t}

be the amplitudes of incident wave, reflected wave and transmitted wave and

I_{i}, I_{r}

and

I_{t}

be the corresponding intensities. Then, choose the correct alternative.

Q. Two strings

1

and

2

make a junction of partly reflected and partly transmitted waves. The linear mass density of string

2

is four times that of string

1

, and the boundary between the two strings is at

x = 0

. The expression for the incident wave is

y_{i} = A_{i} cos (k_{1} x - ω_{1} t)

. Which of the following relations is correct, if average power carried by the incident wave, transmitted wave and reflected wave are

P_{i}, P_{t} & P_{r}

respectively? [Assume tension in string

1

and

2

to be the same]

A wave is travelling in string 1 with velocity $v_{1}$ . It is then both reflected and transmitted from a joint to string 2 where the velocity is $v_{2}$ . If $A_{i}$ represents the incident amplitude, What are the reflected and transmitted amplitudes?

Q. If the amplitude of incident wave is A, what are amplitudes of reflected and transmitted waves ?

Q. A wave pulse traveling on a two piece string, gets partially reflected and partially transmitted at the junction. The reflected wave is inverted in shape as compared to incident one. If the incident wave has wavelength

λ

and transmitted wave has

λ^{'},

then

Join BYJU'S Learning Program

In the shown figure, answer the following question. If pi,pr,pt are powers of incident, reflected and transmitted waves and Ii,Ir,It the corresponding intensities, then under what conditions 75 % of incident energy is transmitted?

In the shown figure, answer the following question.

If $p_{i}, p_{r}, p_{t}$ are powers of incident, reflected and transmitted waves and $I_{i}, I_{r}, I_{t}$ the corresponding intensities, then under what conditions $75 %$ of incident energy is transmitted?