Revision Quiz | Waves for JEE & BITSAT Exams

Question 1

Two closed organ pipes, A and B, have the same length. A is wider than B. They resonate in the fundamental mode at frequencies n_A and n_B respectively.

Question 2

The graph below shows displacement (y) versus distance (x) along the line of a transmission of a longitudinal wave at a given instant.

The positive y-axis is displacement to the right and the negative y-axis is displacement to the left. The pressure maxima positions happen at the positions marked -

Question 3

A stretched string of 1 m length, fixed at both ends, having a mass of 5 x 10^-4 kg is under a tension of 20 N. It is plucked at a point situated at 25 cm from one end. The stretched string would vibrate with a frequency (in Hz) of

Question 4

When a plane wave train transverses a medium, individual particles execute a periodic motion given by the equation y = 5 sin

where the lengths are expressed in centimeters and time in seconds. The phase difference for two positions of the same particles which are occupied at a time interval 0.8 s apart is-

Question 5

An equation y = acos²

represents a wave with-

Question 6

If the amplitude of sound is doubled and the frequency reduced to one-fourth, the intensity of sound at the same place will be–

Question 7

A heavy string is tied at one end to a movable support and to a light thread at the other end as shown in figure. The thread goes over a fixed pulley and supports a weight to produce a tension. The lowest frequency with which the heavy string resonates is 120 Hz. If the movable support is pushed to the right by 10 cm so that the joint is placed on the pulley, then the minimum frequency at which the heavy string can resonate is–

Question 8

A uniform rope hangs from a rigid support with a block attached at the other end. A transverse pulse is produced at the lower end. The speed with which the pulse travels along the rope–

Question 9

A sound source of frequency 250 Hz completes one revolution in 3 sec is revolving in a circle of radius 10 m. The minimum frequency heard at a point 20 m from the center of the circle

Question 10

A train is moving at a speed of 64 m/s towards a source (fixed on the platform) of radiation of frequency 50 GHz. What will be the beat frequency if the radiation reflected by the train is superposed with the emitted radiation?

Question 11

The frequency of the first overtone of a closed pipe of length L₁ is equal to that of the first overtone of an open pipe of length L₂. The ratio of their lengths (L₁ : L₂) is

Question 12

The fundamental frequency of a sonometer wire increases by 6 Hz if its tension is increased by 44% keeping the length constant. Find the change in fundamental frequency of the sonometer wire, if the length of the wire is increased by 20% keeping original tension in the wire?

Question 13

A standing wave is produced on a string clamped at one end free at the other. The length of the string–

Question 14

Two tuning forks of frequency 250 Hz and 256 Hz produce beats. If a maximum is observed just now, after how much time the minimum is observed at the same place -

Question 15

In a stretched string under tension and fixed at both ends, the tension is increased by four time and the length is doubled, the frequency becomes -