Current Electricity and Circuits

Question 1

Multiple choice

The circuit shown in the figure, with R = $\dfrac{1}{3}$$\Omega$, L = $\dfrac{1}{3}$H and C = 3 F has input voltage v (t) = sin 2t. The resulting current i(t) is

5 sin (2t - 53.1⁰)
25 sin (2t + 53.1⁰)
25 sin (2t - 53.1⁰)

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Answer

5 sin (2t + 53.1⁰)

Question 2

Multiple choice

The Thevenin equivalent impedance Z_th between the nodes P and Q in the following circuit is

1
1 + s + ^{$\dfrac{1}{s}$}
2 + s + ^{$\dfrac{1}{s}$}
^{$\dfrac{s^2 + s + 1}{s^2 + 2s +1}$}

Reveal answer Fill a bubble to check yourself

Answer

^{$\left[
\begin{array}
\ 1+j & -1+j \\\\
-1+j & 1+j
\end{array}
\right]$}

Answer

4^_$\Omega$

Answer

50 $\Omega$

Answer

$7.5V \ and \ 2.5\Omega$

Answer

$\dfrac{5}{6}$ $\Omega$

Answer

10 cos (t - 35⁰) + 10 cos ( 2t + 10⁰ - tan^-12)

Answer

$\dfrac{1}{11}$ K$\Omega$

Answer

(0.01 - j0.02) ohm

Answer

$40 \mu A\hspace{0.2cm} and \hspace{0.2cm}16 \hspace{0.1cm} volts$

Answer

5.625 mA and 8.75 V

Question 3

Multiple choice

For the lattice shown in the figure, Z_a = j2^$\Omega$ and Z_b = 2^$\Omega$. Calculate the values of the open circuit impedance parameter [z] = ^{$\left[
\begin{array}
\ Z_{11} & Z_{12} \\
Z_{21} & Z_{22}
\end{array}
\right]$}.

^{$\left[
\begin{array}
\ 1-j & 1+j \\\\
1+j & 1+j
\end{array}
\right]$}
^{$\left[
\begin{array}
\ 1-j & 1+j \\\\
-1+j & 1-j
\end{array}
\right]$}
^{$\left[
\begin{array}
\ 1+j & 1+j \\\\
1-j & 1-j
\end{array}
\right]$}

Reveal answer Fill a bubble to check yourself

Question 4

Multiple choice

In the circuit given below, what value of R_L maximizes the power delivered to R_L?

2.4 ^_$\Omega$
$\dfrac{8}{3}$$\Omega$
6^_$\Omega$

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Question 5

Multiple choice

The maximum power that can be transferred to the load resistor R_L of 100$\Omega$ from the voltage source of 5 V is __________

1 W
10 W
0.25 W
0.5 W

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Question 6

Multiple choice

If R₁ = R₂ = R₄ and R₃ = 1. 1R in the bridge circuit shown in figure, then the reading in the ideal voltmeter connected between a and b is

0.238 V
0.138 V
-0.238 V
1 V

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Question 7

Multiple choice

The impedance looking into nodes 1 and 2 in the given circuit is

100 $\Omega$
5 k$\Omega$
10. 1k$\Omega$

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Question 8

Multiple choice

For the circuit shown in figure, Thevenin's voltage and Thevenin's equivalent resistance at terminals a - b is

$5V \ and \ 2\Omega$
$4V \ and \ 2\Omega$
$3V \ and \ 2.5\Omega$

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Question 9

Multiple choice

Twelve 1$\Omega$ resistances are used as edges to form a cube. The resistance between two diagonally opposite corners of the cube is

$\dfrac{1}{6}$ $\Omega$
$\dfrac{6}{5}$ $\Omega$
$\dfrac{3}{2}$ $\Omega$

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Question 10

Multiple choice

An input voltage v(t) = 10^{$\sqrt 2$} cos(t+10⁰) + 10^{$\sqrt 3$} cos (2t+10^o)V is applied to a series combination of resistance R = 1 ^_$\Omega$and an inductance L = 1 H. The resulting steady state current i(t) in ampere is

10 cos (t + 55⁰) + 10 cos (2t + 10⁰ + tan^-12)
10 cos (t + 55⁰) + 10 ^{$\sqrt{ \dfrac{3}{2} }$} cos (2t + 55⁰)
10 cos (t - 35⁰) + 10 ^{$\sqrt{ \dfrac{3}{2} }$}cos (2t - 35⁰)

Reveal answer Fill a bubble to check yourself

Question 11

Multiple choice

An amplifier without feedback has a voltage gain of 50, input resistance of 1 K$\Omega$ and output resistance of 2.5 K$\Omega$. The input resistance of the current-shunt negative feedback amplifier using the above amplifier with a feedback factor of 0.2, is

$\dfrac{1}{5}$ K$\Omega$
5 K$\Omega$
11 K$\Omega$

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Question 12

Multiple choice

Three identical amplifiers with each one having a voltage gain of 50, input resistance of 1 K$\Omega$and output resistance of 250 $\Omega$, are cascaded. The open circuit voltage gain of the combined amplifier is

49 dB
51 dB
98 dB
102 dB

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Question 13

Multiple choice

A short-circuited stub is shunt connected to a transmission line as shown in figure. If Z₀ = 50 ohm, the admittance Y seen at the junction of the stub and the transmission line is

(0.02 - j0.01) ohm
(0.04 - j0.02) ohm
(0.02 + j0) ohm

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Question 14

Multiple choice

The circuit using a BJT with $\beta$ = 50 and V_BE = 0.7 V is shown in figure. The base current I_B and collector voltage V_C are respectively

$43 \mu A\hspace{0.2cm} and \hspace{0.2cm}11.4 \hspace{0.1cm} volts$
$45 \mu A\hspace{0.2cm} and \hspace{0.2cm}11 \hspace{0.1cm} volts$
$45 \mu A\hspace{0.2cm} and \hspace{0.2cm}10 \hspace{0.1cm} volts$

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Question 15

Multiple choice

Given r_d = 20 k$\Omega$, I_DSS = 10 mA, V_p = -8 V.

I_D and I_DS under DC conditions are respectively

4.500 mA and 11.00 V
7.500 mA and 5.00 V
6.250 mA and 7.50 V

Reveal answer Fill a bubble to check yourself

Current Electricity and Circuits

Current Electricity and Circuits Questions