Explanation:
Given the intensity level 10 m from a point sound source is 85 dB, then;
L1 = 10m, I1= 85dB ...1
The intensity level 50 m away from the same source cal be calculated using the equivalent expression;
when L2 = 50m, I2 = ? ... 2
Solving equation 1 nad 2;
10m = 85db
50m = x
Cross multiplying;
50 * 85 = 10 * x
10x = 50*85
10x = 4250
Divide both sides by 10
10x/10 = 4250/10
x = 425 dB
Hence, the intensity level 50 m away from the same source is 425dB
To transmit sound by radio, the transmitter adds a high frequency carrier wave to the sound signal. This makes the amplitude of the carrier wave change, but the frequency stays the same. ... This form of modulation produces frequencies which are the 'sum and the difference' of the carrier and modulation frequencies.
Explanation: