Home
Class 11
PHYSICS
If the sound level in a room is increase...

If the sound level in a room is increased from 50 dB to 60 dB, by what factor is the pressure amplitude increased ?

Text Solution

Verified by Experts

The correct Answer is:
A
`beta_1=50dB, beta_2=60dB,`
I_1=10^-7W/m^2, I_2=10^-6W/m^2`
`[because beta=10log_10(I/I_0)`
where `I_0=10^-12W/m^2]`
Again, `I_2/I_1=(p_2/p_1)^2=(10^-6/10^-7)=10`
`(where p=pressure amplitude)
`:.(p_2/p_1)^2=10`
`rarr P_2/P_1=sqrt10`
Promotional Banner

Similar Questions

Explore conceptually related problems

A cylinder with a movable piston contains 3 moles of hydrogen at standard temperature and pressure. The walls of the cylinder are made of a heat insulator, and the piston is insulated by having a pile of sand on it. By what factor does the pressure of the gas increase if the gas is compressed to half its original volume ?

A cylinder with a movable piston contains 3 moles of hydrogen at standard temperature and pressure. The walls of the cylinder are made of heat insulator and the piston is insulated by having a pile of sand on it. By what factor does the pressure of the gas increase if the gas is compressed to half its original volume ?

Two audio speakers are kept some distance apart and are driven by the same amplifier system. A person is sitting at a place 6.0 m from one of the speakers and 6.4 m from the other. If the sound signal is continuously varied from 500 Hz to 5000 Hz, what are the frequencies for which there is a destructive interference at the place of the listener? Speed of sound in air = 320 ms^-1

If the intensity of sound is increased by a factor of 30, by how many decibels in the sound level increased :-

(a) The power of sound from the speaker of a radio is 20 mW. By turning the knob of volume control the power of sound is increased to 400 mW, What is the power increase in dB as compared to original power? (b) How much more intense is an 80 dB sound than a 20 dB whisper?

The human ciculatory system can be thought of as a closed system of interconnecting pipes through which fluid is continuously circulated by two pumps the two pumps the right and left verticles of the heart, work as simple two-stroke force pumps. The muscles of the heart regulate the force by contracting and relaxing. the contraction (systole) lasts about 0.2s and a complete systole/diastole (contraction/relaxation) cycle lasts about 0.8s. For flood pressures and speeds in the normal range. the volume flow rate of blood through a blood vessel is directly proportional tot he pressure difference over a length of the vessel and to the fourth power of the radius of the vessel. The total mechanical energy per unit volume of blood just as it leaves the heart is E//V=rhogh+P+rhov^(2) Q. During intense exercise the volume of blood pumped per second by an athlete,s heart increases by a factor of 7, and his blood pressure increases by 20%/by what factor does the power output of the heart increase during exercise?

A 1.5m tall boy is standing at some distance from a 30m tall building. The angle of elevation from his eyes to the top of the building increase from 30^(@) " to " 60^(@) as he walks towards the building. Find the distance he walked towards the building.

If the temperature of the sun were to increase form T to 2T and its radius from R to 2R , then the ratio of the radiant energy received on earth to what it was previously will be

Consider one mole of perfect gas in a cylinder of unit cross section with a piston attached as shown in figure. A spring (spring constant k) is attached (unstretched length L ) to the piston and to the bottom of the cylinder. Initially the spring is unstretched and the gas is in equilibrium. A certain amount of heat Q is supplied to the gas causing an increase of value from V_0 to V_1 . (a) What is the initial pressure of the system ? (b) What is the final pressure of the system ? (c) Using the first law of thermodynamics, write down a relation between Q, P_a , V, V_0 and k.