The impedance of an RLC series circuit is definitely increased if:

Explanation

The impedance ((Z)) in an RLC series circuit is given by the formula:[ Z = sqrt{R^2 + (X_L - X_C)^2} ]where:- ( R ) is the resistance,- ( X_L ) is the inductive reactance,- ( X_C ) is the capacitive reactance.From the formula, we can observe that increasing the inductance (( L )) will increase the inductive reactance (( X_L )), leading to an increase in the overall impedance.Explanations for Wrong Choices:- (a) (C) decreases: Capacitive reactance decreases with decreasing capacitance, but this doesn't necessarily increase the overall impedance.- (b) (R) increases: Increasing resistance (( R )) directly increases the impedance but was not the focus of the question.- (c) (L) decreases: Decreasing inductance would decrease inductive reactance, leading to a decrease in the overall impedance, contrary to the correct answer.So, the correct answer is (d) (L) increases.