NEETPhysicsAlternating Current
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): In a series LCR circuit, if the inductive reactance is twice the capacitive reactance ( X_L = 2X_C ) and the resistance equals the capacitive reactance ( R = X_C ), the current lags the source voltage by 45^ . Reason (R): The rms current in a series LCR circuit is maximum when the inductive reactan
Options
- ABoth Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A)
- BBoth Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of Assertion (A)
- CAssertion (A) is true but Reason (R) is false
- DAssertion (A) is false but Reason (R) is true
Correct answer
B. Both Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of Assertion (A)
Step-by-step solution
For the Assertion (A): The phase angle in a series LCR circuit is given by: = X_L - X_C R Substituting the given values ( X_L = 2X_C and R = X_C ): = 2X_C - X_C X_C = X_C X_C = 1 = 45^ Since X_L > X_C , the circuit is net inductive. In an inductive circuit, the voltage leads the current, meaning the current lags the source voltage by 45^ . Thus, Assertion (A) is true. For the Reason (R): The rms current in a series LCR circuit is I_ rms = V_ rms R^2 + (X_L - X_C)^2 . This current is maximum when X_L = X_C (resonanc