Wave Motion & Waves on String PYQs Set 4 (PDF)

Set 4 of 5 · Questions 91-120 of 122

In the print window choose “Save as PDF”. The file prints without a web address or date line.

Mere Teacher · Previous Year Questions NEET Physics · Wave Motion & Waves on String · Set 4 (Q91-120)
Scan or visit mereteacher.com for free PYQ practice, timed CBT tests, step-by-step solutions and BroBot AI. Answers and solutions are free with a sign-up.
91. $A stretched string resonates with tuning fork frequency 512 Hz when length of the string is 0.5 m . The length ofthe string required to vibrate resonantly with a tuning fork of frequency 256 Hz would be$ (1) $0.25 m$ (2) $0.5 m$ (3) $1 m$ (4) $2 m$ 92. $The phase difference between two waves, represented by y_{1} = 1 0^{- 6} sin (100 t + (\frac{x}{50}) + 0.5) m y_{2} = 1 0^{- 6} cos [100 t + (x /50)] m, where x is expressed in metres and t is expressed in seconds, is approximately.$ (1) $1.07 radians$ (2) $2.07 radians$ (3) $0.5 radians$ (4) $1.5 radians$ 93. $The equation of a wave is represented by y = 1 0^{- 4} sin (100 t - \frac{x}{10}) m, then the velocity of wave will be$ (1) $100 m / s$ (2) $4 m / s$ (3) $1000 m / s$ (4) $10 m / s$ 94. $Two uniform wires of the same material are vibrating under the same tension. If the first overtone of the first wire is equal to the second overtone of the second wire and radius of the first wire is twice the radius of the second wire then the ratio of the lengths of the first wire to second wire is$ (1) $\frac{1}{3}$ (2) $\frac{1}{4}$ (3) $\frac{1}{5}$ (4) $\frac{1}{6}$ 95. $A string is clamped at both the ends and it is vibrating in its 4^{th} harmonic. The equation of the stationary wave is. Y = 0.3 sin (0.157 x) cos (200 πt) The length of the string is (All quantities are in SI units.)$ (1) $20 m$ (2) $80 m$ (3) $40 m$ (4) $60 m$ 96. $When a wave travels in a medium, displacement of a particle is given by y = asin 2 π (bt - cx) where a, b, c are constants. The maximum particle velocity will be twice the wave velocity if$ (1) $b = ac$ (2) $b = \frac{1}{ac}$ (3) $c = πa$ (4) $c = \frac{1}{πa}$ 97. $A rope supports of standing wave with a total of 4 nodes. It is fixed at the both ends. Calculate the wavelength of the wave if the length of rope is 6 m .$ (1) $0.67 m$ (2) $1.2 m$ (3) $1.5 m$ (4) $4 m$ 98. $The equation of a simple harmonic wave is given by y = 6 sin 2 π (2 t - 0.1 x), where x and y are in mm and t is in seconds. The phase difference between two particles 2 mm apart at any instant is$ (1) $54^{\circ}$ (2) $72^{\circ}$ (3) $18^{\circ}$ (4) $36^{\circ}$ 99. $The equation of the wave is y = 10 sin (\frac{2 πt}{30} + α) . If the displacement is 5 cm at t = 0 then the total phase at t = 7.5 s will be (sin 30^{\circ} = 0.5)$ (1) $\frac{π}{3} rad$ (2) $\frac{π}{2} rad$ (3) $\frac{2 π}{5} rad$ (4) $\frac{2 π}{3} rad$ 100. $Which of the following equations represents a travelling wave?$ (1) $y = A e^{- x^{2}} (vt + θ)$ (2) $y = Asin (15 x - 2 t)$ (3) $y = A e^{x} cos (ωt - θ)$ (4) $y = Asin xcos ωt$ 101. $A radar sends an electromagnetic signal of electric field (E_{0}) = 2.25 V/m and magnetic field (B_{0}) = 1.5 x 1 0^{- 8} T which strikes a target on line of sight at a distance of 3 km in a medium. After that, a pail of signal (echo) reflects back towards the radar vitli same velocity and by same path. If the signal was transmitted at time t_{0} from radar, then after how much time echo will reach to the radar?$ (1) $2. 0 x 1 0^{- 5} s$ (2) $4. 0 x 1 0^{- 5} s$ (3) $1. 0 x 1 0^{- 5} s$ (4) $8. 0 x l 0^{- 5} s$ 102. $For production of beats the two sources must have$ (1) $different frequencies and same amplitude$ (2) $different frequencies$ (3) $different frequencies, same amplitude and same phase$ (4) $different frequencies and same phase$ 103. $A wire of length 2 L, is made by joining two wires A and B of same length but different radii r and 2 r and made of the same material. It is vibrating at a frequency such that the joint of the two wires forms a node. If the number of antinodes in wire A is p and that in B is q then the ratio p : q is:$ (1) $3 : 5$ (2) $4 : 9$ (3) $1 : 2$ (4) $1 : 4$ 104. $A stretched string is vibrating in the second overtone, then the number of nodes and antinodes between the ends of the string are respectively$ (1) $3 and 2$ (2) $2 and 3$ (3) $4 and 3$ (4) $3 and 4$ 105. $A stretched string fixed at both ends has m nodes, then the length of the string will be$ (1) $(m - 1) \frac{λ}{2}$ (2) $\frac{( m + 1 ) λ}{2}$ (3) $\frac{mλ}{2}$ (4) $(m - 2) \frac{λ}{2}$ 106. $In a sonometer experiment, the string of length L under tension vibrates in second overtone between two bridges. The amplitude of vibration is maximum at$ (1) $\frac{L}{3}, \frac{2 L}{3}, \frac{5 L}{6}$ (2) $\frac{L}{8}, \frac{L}{4}, \frac{L}{2}$ (3) $\frac{L}{2}, \frac{L}{4}, \frac{L}{6}$ (4) $\frac{L}{6}, \frac{L}{2}, \frac{5 L}{6}$ 107. $If n_{1}, n_{2} and n_{3} are the fundamental frequencies of three segments into which a string is divided, then the original fundamental frequency n of the string is given by:$ (1) $\frac{1}{n} = \frac{1}{n _{1}} + \frac{1}{n _{2}} + \frac{1}{n _{3}}$ (2) $\frac{1}{n} = \frac{1}{n _{1}} + \frac{1}{n _{2}} + \frac{1}{n _{3}}$ (3) $n = n_{1} + n_{2} + n_{3}$ (4) $n = n_{1} + n_{2} + n_{3}$ 108. $A glass tube is open at both the ends. A tuning fork of frequency f resonates with the air column inside the tube. Now the tube is placed vertically inside water so that half the length of the tube is filled with water. Now the air column inside the tube is in unison with another fork of frequency f^{’} . Then$ (1) $f^{’} = f$ (2) $f^{’} = 4 f$ (3) $f^{’} = 2 f$ (4) $f^{’} = f /2$ 109. $The length of the wire between two ends of a sonometer is 100 cm. What should be the positions of two bridges below the wire so that the three segments of the wire have their fundamental frequencies in the ratio 1:3: 5.$ (1) $\frac{1500}{23} cm, \frac{500}{23} cm$ (2) $\frac{1500}{23} cm, \frac{300}{23} cm$ (3) $\frac{300}{23} cm, \frac{1500}{23} cm$ (4) $\frac{1500}{23} cm, \frac{2000}{23} cm$ 110. $The amplitude and phase of a wave that is formed by the superposition of two harmonic travelling waves, y_{1} (x, t) = 4 sin (kx - ωt) and y_{2} (x, t) = 2 sin (kx - ωt + \frac{2 π}{3}), are: (Take the angular frequency of initial waves same as ω)$ (1) $(3, \frac{π}{6})$ (2) $(23, \frac{π}{6})$ (3) $(6, \frac{2 π}{3})$ (4) $(6, \frac{π}{3})$ 111. $Three harmonic waves having equal frequency v and same intensity I_{o}, have phase angles 0, \frac{π}{4} and -, \frac{π}{4} respectively. When they are superimposed the intensity of the resultant wave is close to:$ (1) $I_{o}$ (2) $0$ (3) $5.8 I_{0}$ (4) $0.2 I_{0}$ 112. $The equation of simple harmonic progressive wave is given by y = asin 2 π (bt - cx) . The maximum particle velocity will be half the wave velocity if c =$ (1) $2 πa$ (2) $\frac{1}{4 π a}$ (3) $\frac{1}{2 π a}$ (4) $4 πa$ 113. $The equation of a simple harmonic wave is given by y = 3 sin \frac{π}{2} (50 t - x), where x and y are in metres and t is in seconds. The ratio of maximum particle velocity to the wave velocity is$ (1) $2 π$ (2) $\frac{3}{2} π$ (3) $3 π$ (4) $\frac{2}{3} π$ 114. $A steel wire with mass per unit length 7.0 \times 1 0^{- 3} kg m^{- 1} is under tension of 70 N. The speed of transverse waves in the wire will be:$ (1) $200 π m/s$ (2) $100 m/s$ (3) $10 m/s$ (4) $50 m/s$ 115. $The wave described by y = 0.25 sin (10 π x - 2 π t), where x and y are in meters and t in seconds, is a wave travelling along the$ (1) $+ vex direction with frequency 1 Hz and wavelength λ = 0.2 m .$ (2) $-ve x direction with amplitude 0.25 m and wavelength λ = 0.2 m .$ (3) $-ve x direction with frequency 1 Hz.$ (4) $+ vex direction with frequency π Hz and wavelength λ = 0.2 m .$ 116. $Two strings (A, B) having linear densities μ_{A} = 2 \times 10^{- 4} kg / m and, μ_{B} = 4 \times 10^{- 4} kg / m and lengths L_{A} = 2.5 m and L_{B} = 1.5 m respectively are joined. Free ends of A and B are tied to two rigid supports C and D, respectively creating a tension of 500 N in the wire. Two identical pulses, sent from C and D ends, take time t_{1} and t_{2}, respectively, to reach the joint. The ratio t_{1} / t_{2} is :$ (1) $1.90$ (2) $1.67$ (3) $1.08$ (4) $1.18$ 117. $A wire PQ has length 4.8 m and mass 0.06 kg . Another wire QR has length 2.56 m and mass 0.2 kg . Both wires have same radii and are joined as a single wire. This wire is under tension of 80 N . A wave pulse of amplitude 3.5 cm is sent along the wire PQ from end P . The time taken by the wave to reach the other end of single wire is(No power is dissipated during propagation)$ (1) $0.1 s$ (2) $0.12 s$ (3) $0.14 s$ (4) $0.16 s$ 118. $With the propagation of a longitudinal wave through a material medium, the quantities transmitted in the propagation direction are$ (1) $energy, momentum and mass$ (2) $energy$ (3) $energy and mass$ (4) $energy and linear momentum$ 119. $A progressive wave travelling along the positive x -direction is represented by y (x, t) = Asin (kx - ωt + φ) . Its snapshot at t = 0 is given in the figure. For this wave, the phase φ is:$ (1) $- \frac{π}{2}$ (2) $π$ (3) $0$ (4) $\frac{π}{2}$ 120. $Doppler shift in frequency does not depend upon$ (1) $The frequency of the wave produced$ (2) $The velocity of the source$ (3) $The velocity of the observer$ (4) $Distance from the source to the listener$