What is the Q of a parallel RLC circuit, if it is resonant at 7.125 MHz, L is 10.1 microhenrys and R is 100 ohms?

To determine the Q of a parallel RLC circuit, you must divide the resistance by the inductive reactance (Q = R / X_L). Be careful not to confuse this with the series RLC formula (Q = X_L / R). Calculate the inductive reactance first: X_L = 2 * π * f * L. Plugging in the provided frequency of 7.125 MHz and inductance of 10.1 µH gives X_L = 2 * 3.1416 * 7.125 * 10.1 ≈ 452.1 ohms. Finally, divide the given resistance (100 ohms) by the calculated reactance. Q = 100 / 452.1 ≈ 0.221.