Current Electricity and Circuits

Question 1

Multiple choice

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

Z_i and Z₀ of the circuit are respectively

2 M$\Omega$ and 2 k$\Omega$
Infinity and 2 k$\Omega$
Infinity and $\frac{20}{11} k \Omega$

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Answer

$2 M \Omega \hspace{0.2cm} and \hspace{0.2cm} \frac{20}{11} k \Omega$

Question 2

Multiple choice

The input resistance R_i of the amplifier shown in the figure is

$\frac{30}{4} k \Omega$
40 k^$\Omega$
infinite

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Answer

10 k^$\Omega$

Question 3

Multiple choice

A 30-Volts battery with zero source resistance is connected to a coaxial line of characteristic impedance of 50 Ohms at t = 0 second terminated in an unknown resistive load. The line length is that it takes 400 Js for an electromagnetic wave to travel from source end to load end and vice-versa. At t = 400ى s, the voltage at the load end is found to be 40 Volts.

The load resistance is

25 Ohms
50 Ohms
75 Ohms
100 Ohms

Reveal answer Fill a bubble to check yourself

Answer

7.14 V to 7.43 V

Answer

V₀₁ - V₀₂ = V_T In 2

Answer

1cos ^{_{$(\omega t)$}} mV

Answer

5 V and 25 V

Answer

i₆ = 5 A

Answer

1252^$\Omega$

Answer

adding an inductance in series with Z

Answer

$ - \dfrac{V_s}{R_2}$

Question 4

Multiple choice

A 30-Volts battery with zero source resistance is connected to a coaxial line of characteristic impedance of 50 Ohms at t = 0 second terminated in an unknown resistive load. The line length is that it takes 400 Js for an electromagnetic wave to travel from source end to load end and vice-versa. At t = 400ى s, the voltage at the load end is found to be 40 Volts.

The steady-state current through the load resistance is

1.2 Amps
0.3 Amps
0.6 Amps
0.4 Amps

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Question 5

Multiple choice

For the Zener diode shown in the figure, the Zener voltage at the knee is 7 V. The knee current is negligible and the Zener dynamic resistance is 10 ^$\Omega$. If the input voltage (V_i) ranges from 10 V to 16 V, what will be the range of out put voltage (V₀)?

7.00 V to 7.29 V
7.14 V to 7.29 V
7.29 V to 7.43 V

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Question 6

Multiple choice

In the Op-Amp circuit shown, assume that the diode current follows the equation I = I_s exp (V/V_T). For V_i = 2V, V₀ = V₀₁, and for V_i = 4 V, V₀ = V₀₂. The relationship between V₀₁ and V₀₂ is

V₀₂ = $\sqrt{2}$V₀₁
V₀₂ = e² V₀₁
V₀₂ = V₀₁ In 2

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Question 7

Multiple choice

In the circuit shown below, assume that the voltage drop across a forward biased diode is 0.7 V. The thermal voltage V_t = kT/q = 25 mV and small signal input v_i = V_p cos $(\omega t)$ where V_p = 100 mV.

The ac output voltage v_ac is

0.25cos ^{_{$(\omega t)$}} mV
2cos ^{_{$(\omega t)$}}mV
22cos ^{_{$(\omega t)$}} mV

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Question 8

Multiple choice

In the given circuit, the values of V₁ and V₂ respectively are

10 V and 30 V
15 V and 35 V
0 V and 20 V

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Question 9

Multiple choice

Consider the configuration shown in the figure which is a portion of a larger electrical network For R = 1^$\Omega$ and currents i1 = 2 A, i4 = - 1A, i5 = - 4 A, which one of the following is TRUE?

i₃ =- 4 A
Data is sufficient to conclude that the supposed currents are impossible
Data is insufficient to identify the currents i₂, i₃, and i₆

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Question 10

Multiple choice

Consider the common emitter amplifier shown below with the following circuit parameters.

B = 100, g_m = 0.3861 A/V, r₀= ^_$\infty$, r_p = 259 W, R_S = 1k W, R_B = 93kW, R_C = 250 W, R_L = 1k W, C₁= ^_$\infty$and C₂ = 4.7mF.

The resistance seen by the source Vs is

258^$\Omega$
93 K^$\Omega$
$\infty$

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Question 11

Multiple choice

Consider an impedance Z = R + jX marked with point P in an impedance Smith chart as shown in figure. The movement from point P along a constant resistance circle in the clockwise direction by an angle 45c is equivalent to

adding a capacitance in series with Z
adding an inductance in shunt across Z
adding a capacitance in shunt across Z

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Question 12

Multiple choice

In the op-amp circuit given in the figure, the load current i_L is

$ \dfrac{V_s}{R_2}$
$- \dfrac{V_s}{R_L}$
$ \dfrac{V_s}{R_1}$

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Question 13

Multiple choice

What is the order of magnitude of the electric resistance of dry human body?

10²Ohm
10⁴Ohm
10⁶Ohm
10⁸Ohm

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Question 14

Multiple choice

If resistance decreases, then the current will ___________.

increase
remain the same
decrease
double
constant

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Question 15

Multiple choice

Consider if three resistors R1, R2, R3 are connected in parallel and dissipate 20 W by each resistor. Calculate total power?

20 W
1 W
30 W
60 W
3 W

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Current Electricity and Circuits

Current Electricity and Circuits Questions