List of top Physics Questions on Transverse and longitudinal waves asked in CBSE Class XI

A steel wire has a length of 12.0 m and a mass of 2.10 kg. What should be the tension in the wire so that speed of a transverse wave on the wire equals the speed of sound in dry air at 20 °C = 343 m s–1 .

A wire stretched between two rigid supports vibrates in its fundamental mode with a frequency of 45 Hz. The mass of the wire is 3.5 × 10–2 kg and its linear mass density is 4.0 × 10–2 kg m–1. What is (a) the speed of a transverse wave on the string, and (b) the tension in the string?

For the travelling harmonic wave 

y(x, t) = 2.0 cos 2π (10t – 0.0080 x + 0.35) 

where x and y are in cm and t in s. Calculate the phase difference between oscillatory motion of two points separated by a distance of 

(a) 4 m, 

(b) 0.5 m, 

(c) \(\frac{λ}{2}\), 

(d) \(\frac{3λ}{4}\)

A transverse harmonic wave on a string is described by

 y(x, t) = 3.0 sin (36 t + 0.018 x + \(\frac{π}{4}\)) 

where x and y are in cm and t in s. The positive direction of x is from left to right. 

(a) Is this a travelling wave or a stationary wave ? If it is travelling, what are the speed and direction of its propagation ? 

(b) What are its amplitude and frequency ? 

(c) What is the initial phase at the origin ?

A hospital uses an ultrasonic scanner to locate tumours in a tissue. What is the wavelength of sound in the tissue in which the speed of sound is 1.7 km s–1 ? The operating frequency of the scanner is 4.2 MHz
A bat emits ultrasonic sound of frequency 1000 kHz in air. If the sound meets a water surface, what is the wavelength of (a) the reflected sound, (b) the transmitted sound? Speed of sound in air is 340 m s –1 and in water 1486 m s–1 .
A string of mass 2.50 kg is under a tension of 200 N. The length of the stretched string is 20.0 m. If the transverse jerk is struck at one end of the string, how long does the disturbance take to reach the other end?