Given below are two statements :
Statement I : When the frequency of an a.c. source in a series LCR circuit increases, the current in the circuit first increases, attains a maximum value and then decreases.
Statement II : In a series LCR circuit, the value of power factor at resonance is one.
In the light of given statements, choose the most appropriate answer from the options given below:
Statement I : When the frequency of an a.c. source in a series LCR circuit increases, the current in the circuit first increases, attains a maximum value and then decreases.
Statement II : In a series LCR circuit, the value of power factor at resonance is one.
In the light of given statements, choose the most appropriate answer from the options given below:
- (A)Statement I is incorrect but Statement II is true.
- (B)Both Statement I and Statement II are false.
- (C)Statement I is correct but Statement II is false.
- (D)Both Statement I and Statement II are true.✓ Correct
Answer: (D)
Solution
Statement I is correct: In a series LCR circuit, as frequency increases from low values, the impedance decreases (capacitive reactance dominates initially), current increases, reaches maximum at resonance, then decreases as inductive reactance dominates at higher frequencies.
Statement II is correct: At resonance, , so impedance and power factor .
Both statements are true.
Statement II is correct: At resonance, , so impedance and power factor .
Both statements are true.
JEE Main · 2023 · 12 Apr 2023 · Shift 1 · Single correct option