MHT CET20255 May 2025Evening ShiftPhysicsAlternating CurrentActual
The value of alternating e.m.f. (E) in the given circuit is
Options
- A30 V
- B60 V
- C50 V
- D110 V
Correct answer
C. 50 V
Step-by-step solution
A series LCR circuit has the voltage across the inductor as V_L = 20 V , across the capacitor as V_C = 50 V , and across the resistor as V_R = 40 V . The resistor voltage is in phase with the current, while the inductor voltage leads by 90^ and the capacitor voltage lags by 90^ . Thus V_L and V_C differ in phase by 180^ . The alternating e.m.f. is the phasor sum: E = V_R^2 + (V_L - V_C)^2 Substituting the values: E = (40)^2 + (20 - 50)^2 = 1600 + 900 = 2500 = 50 V Final answer: 50 V