Power of a Source: Calculating Intensity & Power

In summary, power and intensity of a source are related but different concepts. Power refers to the rate at which energy is transferred, while intensity is a measure of how concentrated that energy is. The power of a source can be calculated by multiplying the voltage and current, while the intensity can be expressed in watts per square meter. As the distance from a source increases, both the power and intensity decrease due to the inverse square law. Various factors such as type of source, distance, and surrounding conditions can affect the power and intensity of a source.
  • #1
Amith2006
427
2
Sir,
A loud speaker having a circular opening of diameter 20 cm is emitting sound waves uniformly. The intensity of sound at the opening is 0.2 milli watt/m^2. What is the power radiated by the source?
I solved it in the following way:
Intensity = power/Area
Here Area = (pi)R^2
= 3.14 x 0.01
= 0.0314 m^2
Power = 0.2 x 0.0314 milli watts
= 6.28 x 10^(-6) watts
Is it right?
 
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  • #2
Looks correct to me. Did you think it was too easy?
 
  • #3


Hello,
Your calculation appears to be correct. The power radiated by the source can be calculated by multiplying the intensity by the area of the circular opening of the loudspeaker. In this case, the power is 6.28 x 10^(-6) watts. This is a small amount of power, but it can still produce a significant amount of sound due to the efficiency of the loudspeaker. It is important to accurately calculate the power of a source in order to understand its capabilities and potential impact. Thank you for sharing your solution.
 

What is the difference between power and intensity of a source?

The power of a source refers to the rate at which energy is transferred or the amount of energy produced per unit time. On the other hand, intensity refers to the amount of power that is emitted per unit area. In simpler terms, power is the total amount of energy produced, while intensity is a measure of how concentrated that energy is.

How do you calculate the power of a source?

The power of a source can be calculated by multiplying the voltage and current of the source. This is known as the power formula (P = V x I). In other cases, the power of a source can also be calculated by measuring the work done over time, using the formula P = W/t.

What is the unit of measurement for power and intensity?

The unit of measurement for power is watts (W), while the unit for intensity is watts per square meter (W/m2). However, in some cases, the unit for intensity can also be expressed in decibels (dB) or milliwatts per square centimeter (mW/cm2).

How does the distance from a source affect its power and intensity?

As the distance from a source increases, both the power and intensity decrease. This is because the same amount of energy is now spread over a larger area. The inverse square law states that the intensity of a source is inversely proportional to the square of the distance from the source. This means that if the distance is doubled, the intensity decreases by a factor of four.

What factors can affect the power and intensity of a source?

The power and intensity of a source can be affected by various factors, including the type of source, the distance from the source, the angle of emission, and any obstructions in the path of the energy. Other factors such as temperature, humidity, and surrounding materials can also have an impact on the power and intensity of a source.

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