AIIMS2016PhysicsAlternating Current
Assertion : At resonance, L C R series circuit have a minimum current. Reason : At resonance, in LCR series circuit, the current and e.m.f are not in phase with each other.
Options
- AIf both assertion and reason are true and reason is the correct explanation of assertion.
- BIf both assertion and reason are true but reason is not the correct explanation of assertion.
- CIf assertion is true but reason is false.
- DIf both assertion and reason are false.
Correct answer
D. If both assertion and reason are false.
Step-by-step solution
At resonance X_L=X_C or L= 1 C . Because of this impedance of L C R series circuit become equal to resistance of circuit (Z= R^2+ (X_L-X_C )^2 ) . Therefore from I= E Z = E R , at resonance, current in LCR series circuit is maximum. Correspondingly phase angle is also equal to zero. Therefore emf and current are in phase in L C R series circuit.