Analyzing the Setup
In alternating current (AC) circuits, the relationship between voltage and current is defined by the phase difference
This phase difference arises because different components—resistors, inductors, and capacitors—respond differently to changing currents and voltages. Let's break down each component to understand how it affects the phase.
Purely Resistive Circuit
Imagine a circuit with only a resistor
A resistor simply opposes the flow of current without storing any energy. Because of this, the current and voltage rise and fall together in perfect harmony. They are completely in phase.
Therefore, the phase difference ϕ is exactly 0. This matches List-I entry A with List-II entry 2.
Purely Inductive Circuit
Now, consider a purely inductive circuit
An inductor is like a heavy flywheel; it opposes any change in the current flowing through it due to self-induction. When an AC voltage is applied, the inductor fights the rising current, causing the current to lag behind the voltage.
Mathematically, the current lags the voltage by exactly 90∘ or 2π radians. This matches List-I entry B with List-II entry 3.
Purely Capacitive Circuit
Next, let's look at a purely capacitive circuit
A capacitor stores electrical energy. When an AC voltage is applied, the current must flow first to build up the charge on the capacitor's plates before the voltage across it can rise.
Because the current acts first, the current leads the voltage by exactly 90∘ or 2π radians. This matches List-I entry C with List-II entry 1.
The L-C-R Series Circuit
Finally, what happens when we put all three components together in series? The overall phase difference depends on the competition between the inductive reactance XL and the capacitive reactance XC.
The net reactance is XC−XL (or vice versa), and the phase angle ϕ is determined by the ratio of this net reactance to the resistance R.
The formula is given by:
tanϕ=RXC−XL
Taking the inverse tangent, we get:
ϕ=tan−1(RXC−XL)
This matches List-I entry D with List-II entry 4.
Final Conclusion
Putting it all together, we have:
- A → 2
- B → 3
- C → 1
- D → 4
This corresponds perfectly to option (d).