1
GATE EE 2007
+2
-0.6
In the figure, transformer $${T_1}$$ has two secondaries, all three windings having the same number of turns and with polarities having the same number of turns and with polarities as indicated. One secondary is shorted by a $$10\,\Omega$$ resistor $$R,$$ and the other by a $$15\mu F$$ capacitor. The switch $$SW$$ 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
A
$$-25$$ $$V,$$ $$0.0$$ $$A$$
B
very large voltage, very large current
C
$$5.0$$ $$V,$$ $$0.5$$ $$A$$
D
$$5.0$$ $$V,$$ $$-0.5$$ $$A$$
2
GATE EE 2007
+2
-0.6
In the circuit shown in Fig. switch $$S{w_1}$$ is initially CLOSED and $$S{w_2}$$ is OPEN. The inductor $$L$$ carries a current of $$10$$ $$A$$ and the capacitor is charged to $$10$$ $$V$$ with polarities as indicated. $$S{w_2}$$ in initially CLOSED at $$t = {0^ - }$$ and $$S{w_1}$$ is OPENED at $$t=0.$$ The current through $$C$$ and the voltage across $$L$$ at $$t = {0^ + }$$ is
A
$$55$$ $$A,$$ $$4.5$$ $$V$$
B
$$5.5$$ $$A,$$ $$45$$ $$V$$
C
$$45$$ $$A,$$ $$5.5$$ $$V$$
D
$$4.5$$ $$A,$$ $$55$$ $$V$$
3
GATE EE 2006
+2
-0.6
An ideal capacitor is charged to a voltage $${V_0}$$ and connected at $$t=0$$ across an ideal inductor $$L.$$ (The circuit now consists of a capacitor and inductor alone). If we let $${\omega _0} = 1/\sqrt {LC} ,$$ the voltage across the capacitor at time $$t>0$$ is given by
A
$${V_0}$$
B
$${V_0}\cos \left( {{\omega _0}t} \right)$$
C
$${V_0}son\left( {{\omega _0}t} \right)$$
D
$${V_0}{e^{ - {\omega _0}t}}\cos \left( {{\omega _0}t} \right)$$
4
GATE EE 2005
+2
-0.6
A coil of inductance $$10$$ $$H$$ resistance $$40\,\,\Omega$$ is connected as shown in Fig. After the switch $$S$$ has been in connection with point $$1$$ for a very long time, it is moved to point $$2$$ at $$t = 0.$$

If, at $$t = {0^ + }$$, the voltage across the coil is $$120$$ $$V,$$ the value of resistance $$R$$ is

A
$$0$$ $$\Omega$$
B
$$20$$ $$\Omega$$
C
$$40$$ $$\Omega$$
D
$$60$$ $$\Omega$$
EXAM MAP
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