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Match List-I with List-II. List-I (a) Phase difference between current and voltage in a purely resistive AC circuit (b) Phase difference between current and voltage in a purely inductive AC circuit (c) Phase difference between current and voltage in a purely capacitive AC circuit (d) Phase difference between current and voltage in a series LCR AC circuit List-II (i) pi/2; current leads voltage (ii) zero (iii) pi/2; current lags voltage (iv) tan⁻¹((X_C - X_L)/R) Select the correct option:

1. (a)-(i),(b)-(iii),(c)-(iv),(d)-(ii)
2. (a)-(ii),(b)-(iv),(c)-(iii),(d)-(i)
3. (a)-(ii),(b)-(iii),(c)-(iv),(d)-(i)
4. (a)-(ii),(b)-(iii),(c)-(i),(d)-(iv)

Correct answer: (a)-(ii),(b)-(iii),(c)-(i),(d)-(iv)

Solution

AC phase relationships: a purely resistive circuit has current and voltage in phase (zero phase difference). In a pure inductor, voltage leads current, so current lags voltage by pi/2. In a pure capacitor, voltage lags current, so current leads voltage by pi/2. For a series LCR circuit the phase angle is tan⁻¹((X_C - X_L)/R). Hence (a)-(ii), (b)-(iii), (c)-(i), (d)-(iv).

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