Question

What is dBm used to measure in terms of decibels?

(a) Peak amplitude of a signal

(b) Power relative to 1mW

(c) Amplitude of a signal

(d) Volume unit

This question was posed to me by my school principal while I was bunking the class.

I'd like to ask this question from The Decibel topic in division Low Frequency Transistor Amplifier Circuit of Electronic Devices & Circuits

Answer 1

The correct option is (c) Amplitude of a signal

The explanation is: We use dBm to measure the power relative to 1mW. It is generally compared relative to a 600Ω impedance, which equates to a voltage level of 0.775V. The m stands for milliwatts. The derivate dBm0 stands for dBm measured at zero transmission level point.