Waves MCQ Level - 1


10 Questions MCQ Test Topic wise Tests for IIT JAM Physics | Waves MCQ Level - 1


Description
This mock test of Waves MCQ Level - 1 for Physics helps you for every Physics entrance exam. This contains 10 Multiple Choice Questions for Physics Waves MCQ Level - 1 (mcq) to study with solutions a complete question bank. The solved questions answers in this Waves MCQ Level - 1 quiz give you a good mix of easy questions and tough questions. Physics students definitely take this Waves MCQ Level - 1 exercise for a better result in the exam. You can find other Waves MCQ Level - 1 extra questions, long questions & short questions for Physics on EduRev as well by searching above.
QUESTION: 1

The equation of a wave disturbance is given as :
 where X and y are in metres and t in seconds. Choose the wrong statement:

Solution:

y=0.02cos(π/2+50π∗t)cos(10π∗x)

At x=0.3m
y=0.02cos(π/2+50π∗t)cos(3π) = −0.02cos(π/2+50π∗t) (It is right)

Now compare the given equation by the standard stationary wave equation,

y=Acos(ϕ+ω∗t)cos(2π/λ∗x)

2π/λ=10π, λ=0.2m (it is also right)

At x=0.15m, 

y=0.02cos(π/2+50π∗t)cos(π/2),

and

v=Aω=0.02∗50π=πms−1

so option d is incorrect.

QUESTION: 2

In a plane progressive harmonic wave particle speed is always less than the wave speed if:
(where A is wavelength of wave)

Solution:


Let equation of a plane progressive harmonic wave be

wave speed 
and maximum particle speed 
Given that vp < v

The Correct answer is : amplitude of wave is less than 

QUESTION: 3

Which of the following is not the standard form of a sine wave?

Solution:

Standard form of a sine wave is


With these substitutions we can see that Equation (1) can be written as options (b).
The correct answer is:  

QUESTION: 4

Two sound source are moving in opposite directions with velocities v1 and v2(v1 > v2). Both are moving away from a stationary observer. The frequency of both the sources is 900 Hz. What is the value of v1 - v2 so that the beat frequency observed by the observer is 6 Hz. Speed of sound v = 300 mis. Given, that v1 and v2 « v.

Solution:





The correct answer is: 2 m/s

QUESTION: 5

String 1 has twice the length, twice the radius, twice the tension and twice the density of another string 2. The relation between the fundamental frequencies of 1 and 2 is :

Solution:



(m = mass per unit length =pS)


The correct answer is: f2 = 4f1

QUESTION: 6

A string of length L is stretched by L/20 and speed of transverse wave along it is v. The speed of wave when it is stretched by L/10 will be : (assume the Hooke’s law is applicable)

Solution:


The correct answer is: √2v

QUESTION: 7

Speed of transverse wave in a string of density 100 kglm3 and area of cross-section 10 mm2 under the tension of 103 N is :

Solution:


Here, m = mass per unit length = pS


The correct answer is: 1000 m/s

QUESTION: 8

A wave represented by the equation y1 = Acos(kx- ωt), is superimposed with another wave to form a stationary wave such that the point x = 0 is a node. The equation of the other wave is :

Solution:

y=y1 + y2
At x = 0, y = 0 for all values of t only when

The correct answer is: 

QUESTION: 9

The frequency changes by 10% as the source approaches a stationary observer with constant speed vs. What would be the percentage change in frequency as the source recedes the observer with the same speed ? Given, that vs « v ( v = speed of sound in air)

Solution:

QUESTION: 10

A heavy rope is suspended from a rigid support. A wave pulse is set up at the lower end, then :

Solution:

Due to weight of the rope, the tension will increase along the rope from the lower end to the upper end. Hence, the pulse will travel with increasing speed as

The correct answer is: the pulse will travel with increasing speed

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