Q.

A circuit with an electrical load having impedance ... is connected with an AC source as shown in the diagram. The source voltage varies in time as V(t)=300 sin(400t)V, where t is time in seconds. List-I shows various options for the load. The possible currents i(t) in the circuit as a function of time are given in List-II.          [2025]

Choose the option that describes the correct match between the entries in List-I and those in List-II.

1 (P) → (3), (Q) → (5), (R) → (2), (S) → (1)  
2 (P) → (1), (Q) → (5), (R) → (2), (S) → (3)  
3 (P) → (3), (Q) → (4), (R) → (2), (S) → (1)  
4 (P) → (1), (Q) → (4), (R) → (2), (S) → (5)  

Ans.

(1)

Given V(t)=300sin(400t)

i0=30030=10 A,    ϕ=0

So,  (P)→(3)

Z=R2+(ωL)2

=302+(400×100×10-3)2=50 Ω

∴  i0=30050=6 A

and ϕ=tan-1(ωLR)=53°

i.e., the current lags by 53°

So,  (Q)→(5)

(R)  Z=(30)2+(1400×500×10-6-400×25×10-3)2

=302+402=50 Ω

So,  (R)→(2)

(S)  Z=602+(150×10-6×400-125×10-3×400)2

=602+(50-50)2=60Ω

∴  i0=30060=5A

So,  (S)→(1)