A signal travels through a transmission medium and its power is reduces to one forth.  Calculate the attenuation.

Expert Answers
kjcdb8er eNotes educator| Certified Educator

In optics, attenuation is related to the ratio of the input power to the output power of the signal. The equation for attenuation is:

Attenuation (dB) = 10 * log( input power / output power )

According to the problem statement, input power / output power = 1/4

Therefore,

Attenuation (dB) = 10 * log( input power / output power ) = 10 log( 1/4 ) = 10 * -0.6 = -6 dB.