1) The K.E and P.E of a particle executing SHM with amplitude A will be equal to when its displacement is:

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Moris Carroll
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2 1) The K.E and P.E of a particle executing SHM with amplitude A will be equal to when its displacement is: 2) The bob of simple Pendulum is a spherical hallow ball filled with water. A plugged hole near the bottom of the oscillating bob gets suddenly unplugged. During observation, till water is coming out, the time period of oscillation would: a) Remain Unchanged b) Increase towards a saturation value c) First increase and then decrease to the original value d) First decrease and then increase to the original value

3 3) If two tuning forks A and B are sounded together, they produce 4 beats per second, A is then slightly loaded with wax, they produce beats when sounded again. The frequency of A is 256Hz. The frequency of B will be: a) 250Hz b) 252Hz c) 260Hz d) 262Hz 4) There are three sources of sound of equal intensity with frequencies 400, 401 and 402 vibrations/sec. The number of beats heard per second is: a) 0 b) 1 c) 2 d) 3

4 5) Two pulses in a stretched string whose centers are initially 8cm apart are moving towards each other as shown in the figure. The speed of each pulse is 2cm/s. After 2 second, the total energy of the pulse will be: a) Zero 8cm b) Purely Kinetic Energy c) Purely Potential Energy d) Partially Kinetic Energy and Potential Energy 6) The Stretched string instead of plucked in middle is plucked at a point (1/4 th ) of its length from either of its ends. The frequency of vibration would be: a) Four times when plucked in the middle b) Twice when plucked in the middle c) Eight times when plucked in the middle d) Same as when plucked in the middle

5 7) The Sonometer wire, 100cm in length has a fundamental frequency of 330Hz. The velocity of propagation of transverse wave along the wire is: a) 330 ms -1 b) 660 ms -1 c) 115 ms -1 d) 990 ms -1 8) A sufficiently long closed organ pipe has a small hole at its bottom. Initially, the pipe is empty. Water is poured in to the pipe at a constant rate. The fundamental frequency of the air column in the pipe: a) Constantly increases b) First increases and then becomes constant c) Continuously decreases d) First decreases and then becomes constant

6 9) An increase in intensity level of one decibel implies an increase in intensity of : a) 1.0% b) 3.01% c) 26% d) 0.1% 10) A rocket ship is recording from the earth at a speed 0.2c. The ship emits a signal of frequency 4 x 10 7 Hz. The apparent frequency to an observer on the surface of the earth is : a) b) c) d)

7 11) A particle executing SHM has an acceleration of 0.5ms -2 for a displacement of 2m. Its period is : a) s b) s c) s d) s 12) A wave of frequency 500Hz is propagating at a velocity of 360ms -1. the distance between the two particle with a phase difference of 60 0 is a) 60cm b) 24cm c) 48cm d) 12cm

8 13) A transverse wave is represented by the equation, where the symbols have their usual meaning. The ration (ω/k) has the Dimensions a) [M L T -2 ] b) [M L 0 T -1 ] c) [M 0 L T -1 ] d) [M L 2 T -2 ] 14) The Phase difference between two particles 25m apart, when the wave y = 0.03 sin π[2t 0.01x] travels in a medium, is : a) π/8 b) π/4 c) π/2 d) π

9 15) The temperature at which the speed of sound in air is 1.5 times the speed of sound at 27 0 C is a) b) c) d) 204 K 16) The increase in speed of sound, on increasing the temperature by 10 0 C is a) 0.61ms -1 b) 60ms -1 c) 6ms -1 d) 600ms -1

10 17) A tuning fork produces 5 beats per sec, when sounded together with tuning fork of frequency either 250Hz or 260Hz. The frequency of A is a) 265Hz b) 245Hz c) 255Hz d) 270Hz 18) The variation of speed of sound in a gas with pressure p is best represented by the following curve a) v b) v c) v d) v p p p p

11 19) The quality of sound depends on its: a) Wavelength b) Frequency c) Overtones present d) Intensity 20) The wavelength of light coming from a star shifts towards violet end of the spectrum. This indicates that the star is, a) Approaching the earth b) Receding from earth c) Stationary d) Rotating

12 21) A circular disc has 1200 holes and it is rotating at rate of 720 rpm. The frequency of the note emitted will be a) Hz b) 1.67Hz c) 8400Hz d) 14,400Hz 22) Of the following, the graphs that better represents the variation of frequency f of a vibrating string with the square root of tension is: f f f f a) b) c) d)

13 23) An open organ pipe X is twice as long as a closed pipe Y. The ratio of their fundamental frequencies is, a) 1 : 1 b) 1 : 2 c) 2 : 1 d) 1 : 4 24) A sonometer wire is vibrating in its second overtone. The region between the two bridges contains a) Two nodes and Two antinodes b) Four nodes and Three antinodes c) Three nodes and Two antinodes d) Three nodes and Three antinodes

14 25) In brass string, the velocity of a longitudinal wave is 100 times the velocity of a transverse wave. If the Young s module of brass is Nm 2, then the stress in the wire is a) Nm -2 c) Nm -2 b) 10 9 Nm -2 d) 10 7 Nm -2 26) The reverberation time for a crowded hall when compared to that of an empty hall a) Is more b) Is less c) Is the same d) can t be determined

15 27) The period of the simple pendulum in artificial satellite and freely falling lifts will be a) Zero b) Infinity c) Finite but not Zero d) Unpredictable 28) If hole is drilled along a diameter of the earth and a stone is dropped into the hole then the stone: a) Passes through the hole and escapes from the earth b) Comes to rest at the centre of the earth c) Passes through a certain distance and return back d) Executes SHM about the centre of the earth

16 29) A and B are two hills at a distance 510m apart. A person standing between the hills claps his hands and hears two echoes at the end of 1s and 2s. The velocity of sound in air (in ms -1 ) a) 1020 b) 340 c) 510 d) ) The frequency of wave represented by the equation a) 50Hz b) 25Hz c) 10Hz d) 5Hz

17 31) Percentage increase in tension required to increase the speed of propagation of a wave 25% along a given steel wire is a) 25% b) 50% c) 56.25% d) 62.5% 32) The frequencies of two sources of sound are 180Hz and 484Hz. The time interval between two consecutive beats is a) 4 s b) 0.25 s c) 5 s d) 0.2 s

18 33) A set of 30 tuning forks are arranged in a series in the decreasing order of their frequencies. When two consecutive forks in series are sounded together, they produce 2 beats per second. The first fork has a frequency that is the octave of the last. The frequency of the first fork is: a) 58Hz b) 116Hz c) 174Hz d) none 34) The open pipe is suddenly closed at one end with the result that the frequency of the 3 rd harmonic of the closed pipe is found to be higher by 100Hz than the fundamental frequency of the open pipe. The fundamental frequency of the open pipe is : a) 480Hz c) 240Hz b) 300Hz d) 200Hz

19 35) The distance between the bridges of a sonometer is adjusted such that the wire vibrates in unison with a tuning fork of frequency f x. When the distance between the bridges is decreased by 2% the wire and the fork produce 5beats per second. The value of f x is a) 500Hz b) 400Hz c) 250Hz d) 245Hz 36) The fullness of tone in a fine concert hall is determined by, a) Loudness of direct sound from the source b) Loudness of reverberation sound c) The equilibrium sound level d) The ratio of the loudness reverberant sound to that of the direct sound.

20 37) The effective absorbing surface area of the wall and materials inside a hall measuring 50m x 26m x 8m for a reverberation time with of ls is nearly, a) 10 4 m 2 c) 1.7 x 10 3 m 2 b) 8 x 10 3 m 2 d) none 38) A simple pendulum has time period T 1. The point of 1 suspension is now moved upward according to the relation y = Kt 2,(K=1ms -2 ) where y is the vertical displacement. The time period now becomes T 2. The ratio of a) 5/6 c) 4.5 b) 6/5 d) 1

21 39) A whistling train approaches a junction. An observer standing at junction observes the frequency to be 2.2KHz and 1.8KHz of the approaching and the receding train. Find the speed of the train in ms -1 (Speed of Sound = 300ms -1 ) a) 30 ms -1 b) 10 ms -1 c) 300ms -1 d) 100 ms -1 40) A source emits sound of frequency 600Hz inside water. The frequency heard in air will be equal to ( Velocity of sound in Water = 1500ms -1, Velocity of sound in air = 300ms -1 ) a) 3000Hz c) 600Hz b) 120Hz d) 6000Hz

22 41) A particle executes SHM between x = A and x = +A. The times taken for it go from 0 to A/2 ist 1 and to go from A/2 to A is T 2. Then a) T 1 < T 2 c) T 1 = T 2 b) T 1 > T 2 d) T 1 = 2T 2 42) A sound wave of frequency 500Hz covers a distance of 1000m in 5s between points X and Y. Then the number of waves between X and Y are : a) 500 c) 2500 b) 1000 d) 5000

23 43) Wavelength of two notes in air are 80/195m and 80/193m. Each note produces five beats per second with a third note of a fixed frequency. Calculate the velocity of sound in air. a) 450 ms -1 c) 400 ms -1 b) 425 ms -1 d) 415 ms -1 44) Calculate the velocity of sound in a gas in which two waves of length 50cm and 50.4cm produce 6 beats/sec a) 478ms -1 b) 320ms -1 c) 378ms -1 d) 229ms -1

24 45) When a tuning fork A of unknown frequency is sounded with another tuning fork B of frequency 256Hz then 3 beats/sec are observed. After that A is loaded with wax and sounded, then again 3beats/sec are observed. The frequency of tuning fork A is: a) 250Hz b) 253Hz c) 259Hz d) 262Hz 46) An engine is moving on a circular path of radius 100m with a speed of 20ms -1. What will be the frequency observed by an observer standing stationary at the centre of circular path when engine blows a whistle of frequency 500Hz : a) More than 500Hz b) Less than 500Hz c) 500Hz d) No sound is heard

25 47) A man standing between 2 cliffs fires a gun and hears two successive echoes 1.2sec and 2.2sec after the firing. What is the distance between the cliffs? (v s =300ms -1 ) a) 150m b) 360m c) 660m d) 510m 48) Calculate the intensity level of sound having intensity 10 watt m -2 a) 100dB b) 120dB c) 130dB d) 110dB 49) A resonance air column resonates with a tuning fork of frequency 480Hz at length 0.20 m. Calculate the velocity of sound in air. a) 288ms -1 b) 128ms -1 c) 384ms -1 d) 452ms -1

26 50) Resonance was observed with an air column when its length was 0.25m and again when it was 0.5m. If the frequency of the fork is 512Hz, calculate the velocity of the sound in air. a) 512ms -1 b) 384ms -1 c) 128ms -1 d) 256ms -1 51) Calculate the reverberation time for an auditorium in which sound decays by absorption through 50 decibels in 1.2sec. a) 1.81 sec c) 1.00 sec b) 1.44 sec d) 1.60 sec

27 52) A transfers wave along a stretched string is represented below then which of the following is true a. (1, 7) and (2, 8) are in phase b. (3, 6) and (2, 4) are in phase c. (2, 5) and (5, 8) are not in phase a) Only b is true c) a & c are true b) a & b are true d) a, b & c are all true

28 53) The amplitude of sound wave at a distance of 0.2Km from source is A. What is the amplitude of the wave at a distance of 0.4Km from source. a) A/2 b) A/4 c) 2A d) A 54) The frequencies of two sound waves are 512Hz and 516Hz. What will be the time interval between two consecutive beats? a) 1.0 sec c) 0.25sec b) 0.4 sec d) 0.0 sec

29 55) How many beats are heard per second when there are three sources of equal intensity with frequencies a) 3 beats per sec b) 1 beat per sec c) 0 beat per sec d) 2 beats per sec 56) For what wavelength of waves, does a closed pipe of length 30cm emit the first overtone. a) 35cm b) 44cm c) 38cm d) 40cm

30 57) A brass wire and a steel wire of the same length and diameter are stretched to the same tension. Which wire emits a higher fundamental frequency? a) Brass wire has higher frequency than steel wire b) Steel wire has higher frequency than brass wire c) Both have same frequency d) Data is incomplete 58) A stretched string of length 0.6m vibrates in its third mode. What is the wave length of waves on the string? a) 0.9m b) 1.2m c) 0.3m d) 0.4m

31 59) A spherical and cylindrical surfaces must be avoided in auditorium to avoid because, a) Produces echoes b) Undesirable focusing of sound c) It is not fashionable d) None of the above 60) Echo which has a musical ring is called a) Noise Pollution b) Echelon effect c) Classical music d) Pop music 61) Why sound persisted even after the source stops emitting sound a) Reverberation effect b) Multiple reflection c) Echo d) Just Illusion

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