| a) i. Transverse wave must produce Shearing strain on each element of the medium. Gases has Zero Modulus of Elasticity ii. See Figure b)No. of Beats = 8 |
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| Previous Year Questions of March Examinations from 2010 to 2020 |
| Chapter Name: WAVES |
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Nobody can imagine a world without sound. Sound is a part of our life – musics, ripples, echoes etc. Have a lot of applications. a) Can you say how a bat can ascertain directions and distances without any eyes ? b) Doctors use an ultrasonic scanner to diagnose tumour tissues. If the frequency of the scanner is 4.2 Mhz and the speed of sound wave in the tissue is 1.7 km/s. Find the wavelength of the wave ? c) Obtain the equation of a standing wave. Then plot it to locate the nodal and anti-nodal points ? |
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a) Wave motion is a propagation of energy through a material medium due to repeated periodic motion. i.Transverse waves cannot be propagated through gases. Why? ii. What was the condition assumed by Laplace in correcting Newton’s equation for the velocity of sound in a gas? Write the Newton’s-Laplace equation. b) A source of sound of frequency 256 Hz is in –between a listener and a wall. If the source is moving towards the wall with a velocity of 5 ms-1 , how many beats per second will be heard if the sound travels with a speed of 330ms-1 ? |
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While conducting a resonance column experiment in the laboratory, you can hear the maximum sound at a certain height. a) Explain the phenomenon of sound. b) Show that in a closed pipe at one end, the frequencies of the first three harmonics are in the ratio of ν1 : ν2 : ν3 = 1 : 3 : 5. c) Open pipes are preferred to closed ones in musical instruments. why? |
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A student plucks at the centre of a stretched string and observes the wave pattern produced. a) What type of wave is produced in the string? b) Plot the above wave pattern pictorially. Label the nodes and antinodes on the pattern. |
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The equation for a wave is given. Y = A Sin ( kx + ω t ). a) It is a travelling or stationary wave? b) Draw the stationary waves in a stretched string in the second harmonic. c) Show that the fundamental frequency of an open pipe is twice the fundamental frequency of a closed of the same length. |
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In resonance column experiment, we can hear maximum sound at a certain height. This is due to the phenomenon of resonance. a) Show that for a pipe closed at one end, the frequencies are in the ratio ν1 : ν2 : ν3 = 1: 3: 5. b) Open pipes are preferred to closed pipes in musical instruments. Why? |
| a) A transverse harmonic wave is described by y = 3.0 Sin (0.018x + 36 t), where x and y are in cm The amplitude of this wave is ....... b) Figure below shows the fundamental mode or first harmonic in a stretched string, when a standing wave is formed in the string. Draw the figure that shows the second harmonic in the string. If L is the length of the string and v is the speed of the wave in the string, what are the equations of first and second harmonic frequencies? |
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| The fundamental mode of vibration of a atretched atring is shown in the figure a) Draw the second and third harmonics b) Prove that frequencies produced in the string are in the ratio of 1:2:3 c) Let the fundamental frequency is 45 Hz and the length of the wire is 87.5 cm. If linear density of the wire is 4.0 x 10-2 kg/m. Find the tension in the string |
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| A wave traveling along a string described by y(x, t) = 0.005 Sin (80.0x – 3.0t) in which the numerical constants are in SI units. Calculate the wavelength and frequency of the wave |
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a) Draw diagrams showing the first and third harmonics produced in a closed pipe (b) Write the equation for the fundamental frequency in terms of length of the pipe |
| A steel wire has a length of 12.0 m and a mass of 2.10 kg. What is the tension in the wire if speed of a transverse wave on the wire is 343 ms–1 ? |
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A transverse harmonic wave on a string is described by
y(x, t) = 3.0 sin (36 t + 0.018 x + π/4)
where x and y are in cm and t in s. (a) Is this a travelling wave or a stationary wave ? (b) What are its amplitude and frequency ? (c) What is the initial phase at the origin ? (d) What is the least distance between two successive crests in the wave ? |
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A wave travelling along a string is described by, y(x, t) = 0.005 sin (80.0 x – 3.0 t), in which the numerical constants are in SI units. Calculate (a) the amplitude, (b) the wavelength, and (c) the period and frequency of the wave. |
