### FCC Technician Exam Question Of The Day (T5B09)

Q) What is the approximate amount of change, measured in decibels (dB), of a power increase from 5 watts to 10 watts?

A) 3 dB

The following formula will allow you calculate the ratio in decibels given two different power values.

dB = 10 * Log(Pa / Pb)

Using the figures in the question:

dB = 10 * Log (10 / 5)

dB = 10 * Log(2)

dB = 10 * 0.301

dB = 3.01

which is approximately 3 dB

This question is from the FCC Element 2 Technician Class Question Pool

Effective July 1, 2010 for examinations and is valid until June 30, 2014

A) 3 dB

**NJ2X Notes**:The following formula will allow you calculate the ratio in decibels given two different power values.

dB = 10 * Log(Pa / Pb)

Using the figures in the question:

dB = 10 * Log (10 / 5)

dB = 10 * Log(2)

dB = 10 * 0.301

dB = 3.01

which is approximately 3 dB

This question is from the FCC Element 2 Technician Class Question Pool

Effective July 1, 2010 for examinations and is valid until June 30, 2014