### FCC Technician Exam Question Of The Day (T5B11)

Q) What is the approximate amount of change, measured in decibels (dB), of a power increase from 20 watts to 200 watts?

A) 10 dB

You can use the following formula to calculate the ratio in decibels given two different power values.

dB = 10 * Log(Pa / Pb)

Using the figures in the question:

dB = 10 * Log (200 / 20)

dB = 10 * Log(10)

dB = 10 * 1

dB = 10

A) 10 dB

**NJ2X Notes**:You can use the following formula to calculate the ratio in decibels given two different power values.

dB = 10 * Log(Pa / Pb)

Using the figures in the question:

dB = 10 * Log (200 / 20)

dB = 10 * Log(10)

dB = 10 * 1

dB = 10