Question

The intensity of a sound wave gets reduced by 20% on passing through a slab. The reduction in intensity on passage through two such consecutive slabs is:

Solution

Correct option is

36 %

 

Intensity after passing through one slab

                      

So, intensity after passing through two slabs 

                       

SIMILAR QUESTIONS

Q1

The speed of a wave in a medium is 960 m/s. If 3600 waves are passing through a point in the medium in  minute, then calculate the wavelength.

Q2

What is the frequency of radio waves transmitted by a station, if the wavelength of three waves is 300 meter?

Q3

At a pressure of 105N/m2 the volume strain of water is  Calculate the speed of sound in water. (Density of water = kg/m3).

Q4

At normal temperature and pressure the speed of sound in air is 332 m/s. What will be the speed of sound in hydrogen (i) at normal temperature and pressure, (ii) at 546oC temperature and 3 atmospheric pressure? (Air is 16 times heavier than hydrogen).

Q5

The speed of sound in oxygen is 635 m/s. Find out the speed of sound in a mixture of hydrogen and oxygen in which the ratio of hydrogen and oxygen volumes is 4:1.

Q6

Find out the ratio of the velocity of sound in helium and in nitrogen gases at 300 K temperature. Molecular weights of helium and nitrogen are 4 and 28 respectively.

Q7

At what temperature will the speed of sound in air be double of its speed at 57oC?

Q8

At what temperature the speed of sound in oxygen will be same as that in nitrogen at 14oC? The molecular weights of oxygen and nitrogen are 32 and 28 respectively.

Q9

A wave whose amplitude is 0.07 m and frequency is 400 hertz travels in a medium with a velocity of 300 m/s. Determine the displacement equation of oscillation at a distance x metre from the source due to this wave.

Q10

A is singing a note and at the same time B is singing a note with exactly one-eighth the frequency of the note of A. The energies of the two sounds are equal. The amplitude of the note of B is: