In the figure given below, transformer T1 has two secondaries,

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In the figure given below, transformer T₁ has two secondaries, all three windings having the same number of turns and with polarities as indicated. One secondary is shorted by a 10 Ω resistor R, and the other by a 15 μF capacitor. The swit ch SW is opened (t = 0) when the capacitor is charged to 5 V with the left plate as positive. At t = 0+ the voltage V_P and current I_R are

1. – 25 V, 0.0 A
2. very large voltage, very large current
3. 5.0 V, 0.5 A
4. – 5.0 V, – 0.5 A

Correct Option: D

At t = 0+, re-drawing the circuit as,

Using dot-convention, V_EF = V_E - V_F = 5
V_A has negative polarity as V_F has also the same V_C has negative polarity as V_A has also the same. Since the turns ratio are same, therefore,
V_EF = (– V_AB) = (– V_CD) = 5 volts
⇒ V_CD = – 5volts.

and I_R =	V_CD	= - 0.5 A
	R