Electrical Engineering - Network Theory
Exam Duration: 45 Mins Total Questions : 30
In the circuit of the figure a charge of 600 C is delivered to the 100 V source in 1 min. the value of \({ V }_{ 1 }\) must be
- (a)
240 V
- (b)
120 V
- (c)
60 V
- (d)
30 V
The time constant to the network shown in the figure is
- (a)
2 RC
- (b)
3 RC
- (c)
\(\frac{RC}{2}\)
- (d)
\(\frac{2RC}{3}\)
In the circuit of figure below, bulb A uses 48 W when lit, bulb B uses 22 W when lit and bulb C uses 14.4 W when lit. The additional bulbs in parallel to this circuit, that would be required to below the fuse, are
- (a)
4
- (b)
5
- (c)
6
- (d)
7
In the delta equivalent of the given star connected circuit ,\(\bar { Z_{ QR } } \) is equal to
- (a)
40\(\Omega \)
- (b)
(20+j10)\(\Omega \)
- (c)
\(\left( 5+j\frac { 10 }{ 3 } \right) \Omega \)
- (d)
(10+j30)\( \Omega \)
The Laplace transform of I(t) is given by \(I(s)=\frac { 5 }{ s\left( { s }^{ 2 }+2 \right) } \). As \(t\rightarrow \infty \)the value of I(t) tends to
- (a)
zero
- (b)
1
- (c)
5/2
- (d)
infinite
The parallel RLC circuit shown in figure is in resonance. In this circuit
- (a)
IIR 1<1 mA
- (b)
IIR +ILI>lmA
- (c)
IIR +Icl
- (d)
IIR +Icl>5mA
In the circuit of figure I1 =4sin2tA and I2 =0
Find the value of V1
- (a)
-16 cos 2t V
- (b)
16 cos 2t V
- (c)
4 cos 2t V
- (d)
-4 cos 2t V
In a series resonant circuit, Vc =150 V, VL =150 V and VR =50 V. What is the value of the source voltage?
- (a)
Zero
- (b)
50 V
- (c)
350 V
- (d)
200 V
The figure shows a parallel LC tank circuit. What will be the quality factor?
- (a)
50
- (b)
23.4
- (c)
6.93
- (d)
1.34
The current in the circuit shown in figure is
- (a)
5 A
- (b)
10 A
- (c)
15 A
- (d)
25 A
In a series RLC circuit for lower frequency, power factor is ........ and for higher frequency, power factor is
- (a)
leading, lagging
- (b)
lagging, leading
- (c)
independent of frequency
- (d)
same in both cases
A sine wave voltage is applied across a capacitor.When the frequency of the voltage is increased, the current through capacitor
- (a)
increases
- (b)
decrease
- (c)
remains the same
- (d)
is zero
Find RL for maximum power transfer
- (a)
2.4Ω
- (b)
2.6Ω
- (c)
2.8Ω
- (d)
3.0Ω
The voltage across the 1kΩ resistor between the nodes A and B of the network shown in the given figure is
- (a)
2V
- (b)
3V
- (c)
4V
- (d)
8V
The relation AD -BC =1, (where A, B, Cand Dare the elements of a transmission matrix of a network) is val id for
- (a)
any type of network i.e., both active and passive networks
- (b)
passive but not reciprocal networks
- (c)
active and reciprocal networks
- (d)
passive and reciprocal networks
What conclusion can be drawn regarding the Z parameters for the following network?
- (a)
I1 and I2 are dependent and Z-parameters can be found
- (b)
I1 and I2 are independent and Z-parameters can be found
- (c)
I1 and I2 are dependent and Z-parameters cannot be found
- (d)
I1 and I2 are independent and Z-parameters cannot be found
Given, the current through R is 1=1 A. The value of R is
- (a)
zero
- (b)
2Ω
- (c)
4Ω
- (d)
8Ω
The condition on R, L andC such that the step response y(t) in figure has no oscillations, is
- (a)
\(R\ge{1\over 2}\sqrt{L\over C}\)
- (b)
\(R\ge\sqrt{L\over C}\)
- (c)
\(R\ge 2\sqrt{L\over C}\)
- (d)
\(R=\sqrt{L\over C}\)
In a series RLC circuit R=2kΩ, L =1H and C=\(1\over 100\)μF.The resonant frequency is
- (a)
2 x 104Hz
- (b)
\({1\over \pi}\times10^4Hz\)
- (c)
102Hz
- (d)
2π x 104Hz
The equivalent inductance measured between the terminals 1 and 2 for the circuit shown in figure, is
- (a)
L1 +L2 +M
- (b)
L1 + L2 - M
- (c)
L1 + L2 + 2M
- (d)
L1 + L2 -2M
The Laplace transform of I(t) is given by 1(5) = \({2\over s(1+s)}.\)As t ➝ ∞ the value of I(t) tends to
- (a)
zero
- (b)
1
- (c)
2
- (d)
infinite
In the circuit shown below a charge of 500 C is delivered to the 100V source in 1 min. The value of V1 must be
- (a)
266.8V
- (b)
120V
- (c)
60V
- (d)
30V
For the circuit show in figure, determine the current in (2+j3)\(\Omega\) by using superposition theorem
- (a)
14.08\(\angle\)-31.460
- (b)
14.08\(\angle\)31.460
- (c)
10.08\(\angle\)-31.460
- (d)
10\(\angle\)-31.460
Find Vs which makes /0=7.5 mA.
- (a)
0.603 V
- (b)
0.715 V
- (c)
0.708 V
- (d)
0.705 V
In the circuit shown in figure, it is found that the input AC voltage (V) and current I are in phase. The coupling coefficient is \(K=\frac { M }{ \sqrt { L_{ 1 } } L_{ 2 } } \) , where M is the mutual inductance between the two coils.The value of K and the dot polarity of the coil P-Q are K
- (a)
K =0.25 and dot at P
- (b)
K =0.5 and dot at P
- (c)
K =0.25 and dot at Q
- (d)
K =0.5 and dot at Q
The value of V is
- (a)
41.42 V
- (b)
-60 V
- (c)
30 V
- (d)
-30 V
In the given figure, the value of the source voltage is
- (a)
12 V
- (b)
24 V
- (c)
30 V
- (d)
44 V
In figure, the value of resistance R in \(\Omega \) is
- (a)
10
- (b)
20
- (c)
30
- (d)
40
In the circuit shown in figure, I1 =5 sin 3t A and I2=3cos 3t A
The value of V1 is
- (a)
9(5cas 3t + 3 sin 3t) V (b) 9(5 cas 3t -3 sin 3t) V
- (b)
9(4 cas 3t + 5 sin 3t) V (d) 9(5 cas 3t - 3 sin 3t) V
Consider the following circuit:
If VS1 =6 V and Vs2 =-6 V, then the value of Va is
- (a)
4 V
- (b)
-4 V
- (c)
6 V
- (d)
-6 V