Recent questions in Electrical Circuits and Machines

The rms value of the phasor current $\underline{I}$ in the circuit shown $\text{(in amperes)}$ is _____.

In the circuit shown, the rms value of the voltage across the $ 100 \Omega$ resistor $\text{(in volts)}$ is _________.

The real power drawn by a balanced load connected to a $\text{400 V, 50 Hz,}$ balanced, symmetrical 3-phase, 3-wire, $RYB$ sequence mains is measured using the two-wattme...

In the Maxwell-Wien bridge shown, the detector D reads zero when $C_1=100 nF$ and $R_1=100 k\Omega$. The Q factor of the coil is ______

In the circuit shown below, the safe maximum value for the current $I$ is _______$\text{1.0 A}$$\text{0.5 A}$$\text{0.1 A}$$\text{0.05 A}$

Three $400\;\Omega$ resistors are connected in delta and powered by a $400\;V\;(rms), \;50\;Hz,$ balanced symmetrical $R-Y-B$ sequence, three-phase three-wire mains. The ...

A series $R-L-C$ circuit is excited with an a.c. voltage source. The quality factor $(Q)$ of the circuit is given as $Q=30$. The amplitude of current in $\text{ampere}$ a...

In the circuit diagram, shown in the figure, $S_1$ was closed and $S_2$ was open for a very long time. At $t=0,\;S_1$ is opened and $S_2$ is closed. The voltage across th...

In the a.c. bridge, shown in the figure, $R=10^3$ $\Omega$ and $C=10^{-7}$ $F$. If the bridge is balanced at a frequency $\omega_\circ$, the value of $\omega_\circ$ in ...

The current response of a series $\text R-L$ circuit to a unit step voltage is given in the table. The value of $L$ is __________$H$.

For the circuit, shown in the figure, the total real power delivered by the source to the loads is _____________$\text{kW}$.

A series $\text {R-L-C}$ circuit is excited with a $50\;\text{V}$, $50\;\text{Hz}$ sinusoidal source. The voltages across the resistance and the capacitance are shown in ...

A circuit consisting of dependent and independent sources is shown in the figure. If the voltage at $\text{Node-1}$ is $-1\;\text{V}$, then the voltage at $\text{Node-2}$...

In the Figures (a) and (b) shown below, the transformers are identical and ideal ,except that the transformer in Figure (b) is centre -tapped. Asssuming ideal diodes, the...

In the circuit shown below, maximum power is transferred to the load resistance R${_L}$, when R${_L}$ = $\_\_\_\_$ $\Omega$.

Consider a circuit comprising only resistors with constant resistance and ideal independent DC voltage sources. If all the resistances are scaled down by a factor 10, an...

In the circuit shown below, initially the switch S${_1}$ is open, then capacitor C1 has a charge of 6 coulomb, and the capacitor C2 has 0 coulomb. After s${_1}$ is closed...

In the circuit shown below, a step input voltage of magnitude 5 V is applied at node A at time t = 0. If the capacitor has no charge for t $\leq$ 0, the voltage at node P...

In the circuit shown below, the angular frequency $\omega$ at which the current is in phase with the voltage is $\_\_\_\_\_\_$ rad/s.

Three currents $i_1, i_2$ and $i_3$ meet at a node as shown in the figure below. If $i_1=3\cos(\omega t)$ ampere, $i_2=4\sin(\omega t)$ ampere and $i_3=I_3\cos(\omega t+\...

In the circuit shown below $ (v_1+v_2) =[1\; \sin(2\pi10000t)] + 1\;\sin(2\pi30000t)] \;V.$ The $RMS$ value of the current through the resistor $R$ will be minimum if th...

The current $I_X$ in the circuit given below in $\text{milliampere}$ is $\_\_\_\_\_\_\_.$

In the circuit shown below, $V_s=101\angle 0V, R=10\Omega$ and $\omega L=100\Omega$. The current $I_s$ is in phase with $V_s$. The magnitude of $I_s$ in $\text{milliamper...

A symmetrical three-phase three-wire $RYB$ system is connected to a balanced delta-connected load. The $RMS$ values of the line current and line-to-line voltage are $\tex...

The voltage $v(t)$ shown below is applied to the given circuit. $v(t)=3V$ for $t<0$ and $v(t)=6V$ for $t>0$. The value of current $i(t)$ at $t=1s$, in ampere is _________...

The capacitor shown in the figure is initially charged to $\text{+10 V}$. The switch closes at time $t=0$. Then the value of $V_C(t)$ in volts at time $\text{t=0 ms}$ is ...

The output voltage of the ideal transformer with the polarities and dots shown in the figure is given by$NV_i\sin \omega t$$-NV_i\sin \omega t$$\frac{1}{N}V_i\sin \omega ...

A load resistor $R_L$ is connected to a battery of voltage $E$ with internal resistance $R_i$ through a resistance $R_s$ as shown in the figure. For fixed values of $R_L$...

The current in amperes through the resistor $R$ in the circuit shown in the figure is ______________ $A$.

The linear $I-V$ characteristics of 2-terminal non-ideal dc sources $X$ and $Y$ are shown in the figure. If the sources are connected to a $1\Omega$ resistor as shown, th...

Consider the circuits shown in the figure. The magnitude of the ratio of the currents, i.e., $|I_1/I_2|$, is ___________.

The circuit shown in the figure is in series resonance at frequency $f_c\;Hz$. The value of $V_c$ in volts is _____________ $V$.

If the deflection of the galvanometer in the bridge circuit shown in the figure is zero, then the value of $R_X$ in ohms is _______________ $\Omega.$

The circuit shown in figure was at steady state for $t < 0$ with the switch at position $‘A’$. The switch is thrown to position $‘B’$ at time $t=0$. The voltage V(volts)...

The average real power in watts delivered to a load impedance $Z_L=(4-j2)\Omega$ by an ideal current source $i(t)=4\sin(\omega t+20^\circ)A $ is ____________.

In the circuit shown in the figure, initially the capacitor is uncharged. The switch $‘S’$ is closed at $t=0$. Two milliseconds after the switch is closed, the current th...

A capacitor $’C’$ is to be connected across the terminal $’A’$ and $’B’$ as shown in the figure so that the power factor of the parallel combination becomes unity. The va...

The circuit shown in the figure contains a dependent current source between $A$ and $B$ terminals. The Thevenin’s equivalent resistance is $k\Omega$ between the terminals...

The circuit below incorporates a permanent magnet moving coil milli-ammeter of range $1\;\text{mA}$ having a series resistance of $10\;\text{k}\Omega$. Assuming constant ...

In the circuit shown below, if the source voltage $V_s=100\angle 53.13^\circ$ Volts, then the Thevenin’s equivalent voltage in Volts as seen by the load resistance $R_L$ ...