What is the half-power bandwidth of a resonant circuit that has a resonant frequency of 7.1 MHz and a Q of 150?
Why Half-power (3 dB) bandwidth of a resonant circuit is BW = f_resonant / Q. Here 7,100,000 Hz divided by 150 gives about 47,333 Hz, or 47.3 kHz. Higher Q means a narrower, sharper response; lower Q spreads the response out.
Watch out The 23.67 kHz choice is exactly half the right answer, what you get if you mistakenly divide by 2Q or take only one side of the curve. The answers in hertz come from dividing in the wrong direction or losing the MHz-to-Hz conversion.
BW = f / Q. Divide the resonant frequency by Q, and keep the frequency in hertz before you divide.