JEE MainPhysicsAlternating CurrentMCQ+4 / −1
A series LCR circuit has and and it is connected to ac voltage of amplitude . At frequency lower than resonant frequency, the amplitude of current will be approximately :
- A466 mA
- B312 mA
- C238 mA
- D196 mA
View written solutionFree
Correct answer: C
-
Given data
The circuit is driven at a frequency 60% lower than the resonant frequency.
-
Resonant angular frequency
For a series LCR circuit,
Compute:
-
Operating frequency
“60% lower than resonant frequency” means
-
Reactances at this frequency
Inductive reactance:
Capacitive reactance:
Net reactance:
-
Impedance of the series circuit
-
Current amplitude
-
Option check
- A: ❌
- B: ❌
- C: ✅
- D: ❌
Therefore, the correct option is C.
More from Alternating Current
- The current flowing through an ac circuit is given by I = 5 sin(120 t)A How long will the current take to reach the peak value starting from zero?2022 · MCQ
- A 220 V, 50 Hz AC source is connected to a 25 V, 5 W lamp and an additional resistance R in series (as shown in figure) to run the lamp at its peak brightness, then the value of R (in ohm) will be . Includes diagram2022 · Numerical
- If L, C and R are the self inductance, capacitance and resistance respectively, which of the following does not have the dimension of time?2022 · MCQ
- The equation of current in a purely inductive circuit is . If the inductance is then the equation for the voltage across the inductor, will be : Let …2022 · MCQ
- The frequencies at which the current amplitude in an LCR series circuit becomes times its maximum value, are and . The value of resistance in…2022 · Numerical
- A transformer operating at primary voltage and secondary voltage serves a load of . Assuming the transformer to be ideal with purely resistive load and working on unity power factor, the…2022 · MCQ
- An AC source is connected to an inductance of 100 mH, a capacitance of 100 F and a resistance of 120 as shown in figure. The time in which the resistance having a thermal capacity 2 J/ C will get heated by 16… Includes diagram2022 · Numerical
- A telegraph line of length 100 km has a capacity of 0.01 F/km and it carries an alternating current at 0.5 kilo cycle per second. If minimum impedance is required, then the value of the inductance that needs to be introduced in…2022 · Numerical