CBSE Questions for Class 11 Engineering Physics Waves Quiz 3 - MCQExams.com

The relation between frequency $$\upsilon$$, wavelength $$\lambda$$ and velocity of propagation of wave $$\nu$$ is
  • $$\upsilon = \dfrac{\lambda}{\nu}$$
  • $$\upsilon = \lambda \nu$$
  • $$\upsilon = \dfrac{\nu}{\lambda}$$
  • None of these
Two identical sinusoidal waves each of amplitude $$10 mm$$ with a phase difference of $$90^o$$ are travelling in the same direction in string. The amplitude of the resultant wave is :
  • $$5 mm$$
  • $$10 \sqrt{2} mm$$
  • $$15 mm$$
  • $$20 mm$$
Which of the following waves is udsed in sonography?
  • Radio waves
  • X-rays
  • Ultrasonic waves
  • Gamma rays
Which of the following waves does not travel in vacuum?
  • Seismic waves
  • X-rays
  • Light
  • Radio waves
Ultrasonic waves produced by a vibrating quartz crystal are:
  • only longitudinal
  • only transverse
  • both longitudinal and transverse
  • neither longitudinal nor transverse
Regarding open organ pipe, which of following is correct?
  • Both ends are pressure antinodes
  • Both ends are displacement nodes
  • Both ends are pressure nodes
  • Both (1)and (2)
A simple harmoinic motion is represented by $$F(t) = 10 \, \sin(10\tau + 0.5)$$. The amplitude of the S.H.M. is
  • $$a = 30$$
  • $$a = 20$$
  • $$a = 10$$
  • $$a = 5$$
In the equation $$y=A\sin{(kx-\omega t+{\phi}_{0})}$$ the term phase is defined as:
  • $${\phi}_{0}$$
  • $${\phi}_{0}-\omega t$$
  • $$kx+{\phi}_{0}$$
  • $$kx-\omega t-{\phi}_{0}$$
Displacement time equation of a particle executing SHM is x = A sin(wt + /6). Time taken by the particle to go directly from x = - A/2  to x = +A/2 is
  • $$\pi/\omega$$
  • $$\pi/3\omega$$
  • $$3\pi/\omega$$
  • $$\pi/2\omega$$
The equation of a simple harmonic motion is given by, $$ x=8 \,sin (8 \pi t)+6 cos (8 \pi t)$$, the initial phase angle is 
  • $$tan^{-1} (4/3)$$
  • $$tan^{-1} (3/4)$$
  • $$tan^{-1} (2/3)$$
  • $$tan^{-1} (5/8)$$
Two wave have amplitude ratio 10 : 1 then $$v_{1}/v_{2}$$ is (Approx) - 
  • 10 : 1
  • 1 : 10
  • 2 : 3
  • 3 : 2
A particle starts oscillating from position equal to half the amplitude. What is its initial phase?
  • $$\pi/6$$
  • $$\pi/3$$
  • zero
  • none of these
A single wave is called
  • a wave pulse
  • a crest
  • a trough
  • a crest and a trough
A particle is executing SHM with an amplitude 4 cm. What time does it take to reach the distance equal to amplitude, if the particle starts from rest at t = 0 from the mean position
  • T
  • T/2
  • T/4
  • 3T/4
Phase of a particle gives us
  • the velocity of the particle
  • the direction of motion of the particle
  • the acceleration of the particle
  • the displacement of the particle
Which of the following functions represent a wave 
  • $$(x-vt)^{2}$$
  • $$\log (x+vt)$$
  • $$e^{-(x-vt)^{2}}$$
  • $$\dfrac{1}{x+vt}$$
The equation of a wave traveling in a string can be written as $$y=3 \sin\pi(100t-x)$$cm. Its wavelength is:
  • 3 cm
  • 100 cm
  • 5 cm
  • 2 cm
Three waves $$y _ { 1 } = 2 A \sin \left( \omega t - \dfrac { \pi } { 3 } \right)$$  $$y _ { 2 } = 2 A \sin \left( \omega t + \dfrac { \pi } { 3 } \right)$$ and $$y _ { 3 } = - A \sin ( \omega t )$$ interfere each other. The amplitude of the resultant wave is
  • A
  • zero
  • 2 A
  • 3 A
If two waves of same frequency and amplitude superpose to produce resultant of the amplitude of either wave, then their phase difference is- 
  • $$\pi$$
  • $$2\pi/3$$
  • $$\pi/3$$
  • $$Zero$$
The motion of a particle is said to be simple harmonic 
It it moves to and fro about a fixed point  and given that driving force is towards mean position
  • True
  • False
The phase difference between the displacement and acceleration of particle executing S.H.M. radian is:
  • $$ \pi / 4 $$
  • $$ \pi / 2 $$
  • $$ \pi $$
  • $$ 2 \pi $$
The displacement of a particle executing SMH is given by $$x=0.01{\,\,}sin{\,\,}100\pi(t+0.05).$$ The time period is
  • $$0.01$$sec
  • $$0.02$$sec
  • $$0.1$$sec
  • $$0.2$$sec
The two waves represented by $$y=a \sin (\omega t)$$ and $$y_2=b \cos (\omega t)$$ have a phase difference of
  • $$0$$
  • $$\dfrac{\pi}{2}$$
  • $$\pi$$
  • $$\dfrac{\pi}{4}$$
The displacement of a particle is given by$$x = 3 sin(5\pi t) + 4 cos 5(5 \pi t)$$ The amplitude of the particle is [MP PMT 1999]
  • 3
  • 4
  • 5
  • 7
The frequency of light ray having the wavelength $$3000\ A^o$$ is
  • $$9 \times 10^{13}\ cycles/sec$$
  • $$ 10^{15}\ cycles/sec$$
  • $$90 \ cycles/sec$$
  • $$3000 \ cycles/sec$$
A water wave in a shallow tank passes through a gap in a barrier. What happens to the speed and what happens to the wavelength of the wave as it passes through the gap?
1647118_2762724253204411a27b4961fa66174f.png
  • speed - decreases ; wavelength - decreases
  • speed - decreases ; wavelength - remains constant
  • speed - remains constant ; wavelength - decreases
  • speed - remains constant ; wavelength - remains constant
Wavelength of light of frequency $$100\ Hz$$
  • $$2 \times 10^6\ m$$
  • $$3 \times 10^6\ m$$
  • $$4 \times 10^6\ m$$
  • $$5 \times 10^6\ m$$
In how many parts radio wave frequency is divided 
  • $$2$$
  • $$3$$
  • $$4$$
  • $$5$$
A source of sound of frequency 600 Hz is placed inside water. The speed in water is 1500 m/s and in air it is 300 m/s. The frequency of sound recorded by an observer standing in air is
  • 200 Hz
  • 3000 Hz
  • 120 Hz
  • 600 Hz
The principle of  superposition of waves can not be used to explain wave phenomena like
  • Interference
  • Diffraction
  • Stationary Waves and beats
  • Dispersion
Transverse waves are produced in a long string by attaching its free end to a vibrating tuning fork. Figure shows the shape of a part of the string. The points in phase are

6594.jpg
  • A and D
  • B and E
  • C and F
  • A and G
Human audible frequency range is 20Hz to 20KHz.  If velocity of sound in air is 340m/s, the minimum wavelength of audible sound wave is
  • 0.17mm
  • 1.77mm
  • 17mm
  • 170mm
Two light waves are represented by $$y_{1} =3\sin\omega t$$ and $$y_{2}=4\sin( \omega t+\dfrac{\pi }{3} )$$. The resultant amplitude due to interference will be
  • $$\sqrt{21}$$
  • $$\sqrt{26}$$
  • $$\sqrt{37}$$
  • $$\sqrt{41}$$
During propagation of longitudinal plane wave in a medium, two particles separated by a distance equivalent to one wavelength at an instant will be/have
  • In phase, same displacement
  • In phase, different displacement
  • Different phase, same displacement
  • Different phase, different displacement
A plane progressive wave has frequency $$25 \ Hz$$ and amplitude $$2.5 \times 10^{-5}$$ m and initial phase zero, propagates along the negative x-direction with a velocity of $$300 m/s$$. The phase difference between the oscillations at two points $$6m$$ apart along the line of propagation is :
  • $$\pi $$
  • $$\displaystyle \dfrac{\pi}{2}$$
  • $$2\pi $$
  • $$\displaystyle \dfrac{\pi}{4}$$
The equations of displacement of two waves are given as $$Y_{1}=10 \sin(\pi t+\pi /3)$$ $$Y_{2}=5(\sin3\pi t +\sqrt{3}\cos3\pi t$$), then the ratio of their amplitude is 
  • $$1:2$$
  • $$2:1$$
  • $$1:1$$
  • $$3:1$$
The frequency of vibration of a rod is $$200Hz$$. If the velocity of sound in air is $$340m/s$$, the wave length of the sound produced is 
  • $$1.7m$$
  • $$6.8 m$$
  • $$3.4 m$$
  • $$13.6 m$$
Mark correct option:
  • the phase of transmitted wave always remains unchanged
  • the amplitude of transmitted wave does not depend upon the velocity of wave in media
  • the amplitude of reflected wave and transmitted wave are same to each other for a given incident wave
  • the amplitude of rerflected wave is equal to the amplitude of incident wave
Three waves of equal frequency having amplitudes $$10 \ mm, 4 \ mm$$ and $$7\ mm$$ arrive at a given point with successive phase difference $$\dfrac \pi  2$$. The amplitude of the resulting wave (in mm) is given by:
  • $$7$$
  • $$6$$
  • $$5$$
  • $$4$$
When a transverse plane wave traverses a medium, individual particles execute periodic motion given by the equation  $$y=0.25\cos(2\pi t-\pi x)$$. The phase difference for two positions of same particle which are occupied by time intervals $$0.4 second$$ apart is
  • $$144^{o}$$
  • $$135^{o}$$
  • $$72^{o}$$
  • $$108^{o}$$
The equation of a wave pulse is given as $$y=\displaystyle \frac{0.8}{(4x+5t)+4}$$, the amplitude of the pulse is:
  • $$0.2 \ units$$
  • $$0.4\  units$$
  • $$0.6 \ units$$
  • $$0.8 \ units$$
The displacement of a particle varies according to the relation $$X=4(\cos\pi t+\sin\pi t)$$
The amplitude of the particle is
  • $$-4$$
  • $$4$$
  • $$4\sqrt{2}$$
  • $$8$$
A Sound wave with an amplitude of $$3 cm$$  starts moving towards right from origin and gets reflected at a rigid wall after a second. If  the velocity of the wave is $$340 ms^{-1}$$ and it has a wavelength of $$2 m$$, the equations of incident and reflected waves are
  • $$y = 3\times 10^{-2}\sin \pi (340 t - x), y = -3\times 10^{-2}\sin\pi(340t + x)$$ towards left
  • $$y = 4\times 10^{-2} \sin \pi (340 t + x), y = -4\times 10^{-2}\sin\pi(340t + x)$$ towards left
  • $$y = 5\times 10^{-2} \sin \pi (340 t - x), y = -5\times 10^{-2}\sin\pi(340t - x)$$ towards left
  • $$y = 6\times10^{-2}\sin \pi(340 t - x), y = -6\times 10^{-2}\sin\pi(340t + x)$$ towards left
A man is travelling towards east at 20ms$$^{-1}$$ and sound waves are moving towards east at 340ms$$^{-1}$$. He finds that $$500$$ waves cross him in $$2$$ seconds, the wavelength of the sound wave received by the man is :
  • $$1.28 m$$
  • $$2.28 m$$
  • $$3.28 m$$
  • $$4.28 m$$
The equation $$y=4+2\sin(6t-3x)$$ represents a wave motion with amplitude of
  • $$6 units$$
  • $$2 units$$
  • $$20 units$$
  • $$8 units$$
The equation of a wave travelling on a stretched string is  $$y=4\displaystyle \sin 2\pi(\frac{t}{0.02}-\frac{x}{100})$$  here x, y are in cm and t in seconds. The relative deformation amplitude of medium is
  • 0.02$$\pi $$
  • 0.08$$\pi $$
  • 0.06$$\pi $$
  • 0.01$$\pi $$
A wave of length $$2m$$ is superposed on its reflected wave to form a stationary wave. A node is located at  $$ x=3m$$ The next node will be located at  $$x=$$
  • $$4m$$
  • $$3.75m$$
  • $$3.50m$$
  • $$3.25m$$
The equation of a plane progressive wave is $$y = 0.9 \sin 4\pi [t-\displaystyle \dfrac{x}{2}]$$ , when it is reflected at a rigid support, its amplitude becomes $$2/3$$  of its previous value. The equation
of the reflected wave is :
  • $$y=0.9\displaystyle \sin 4\pi[t+\dfrac{x}{2}]$$
  • $$y=-0.6\displaystyle \sin 4\pi[t+\dfrac{x}{2}]$$
  • $${y}=0.9\displaystyle \sin 8\pi[t-\dfrac{x}{2}]$$
  • $${y}=0.6\displaystyle \sin 4\pi[t+\dfrac{x}{2}]$$
The equation of a progressive wave is $$ y = 0.5 \sin \ 2\pi (\dfrac{t}{0.004} - \dfrac{x}{50})$$, where $$x$$ is in $$cm$$. The phase difference between two points separated by a distance $$5 \ cm$$ at any instant is :
  • $$\dfrac \pi 5 $$
  • $$\dfrac \pi 3 $$
  • $$\dfrac \pi 2 $$
  • $$\pi $$
In a stationary wave that forms as a result of reflection of waves from an obstacle, the ratio of the amplitude at an antinode to the amplitude at node is $$6$$. The percentage of energy transmitted is 
  • $$25\%$$
  • $$49\%$$
  • $$58\%$$
  • $$72\%$$
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