OBJECTIVE (UNIT-I)
1. Three resistances, each are R Ohms, are connected in delta. Their equivalent star value for each resistance
is
[c]
(a)R (b) 3R (c) R/3 (d) 2R
2. If in a circuit the voltage is reduced to half and resistance is doubled, the current will become [d]
(a) four times (b) Double (c) half (d) one fourth
3. A linear resistor is one which obeys
[c]
(a) Ampere’s Law (b) Lenz’s Law (c) Ohm’s Law (d) Kirchhoff’s Law
4. The specific resistance is measured in
[a]
(a)Ω-m (b) Ω/m (c) Ω/m3 (d) Ω/m2
5. Two resistors of 12Ω and 4Ω respectively are connected in series. A short is placed across the
combination. The effective resistance will be
[d]
(a) 4Ω (b) 12Ω (c) 16Ω (d) 0Ω
6. Constant voltage source is
[d]
(a) Active and bilateral (b) passive and bilateral (c) Passive and unilateral
(d) Active and unilateral
7. Kirchhoff laws are valid for
[d]
a) Linear circuits only
b) passive time invariant circuits
c) Non-linear circuits only
d) both linear and non linear
8. A star arrangement of resistance has each resistance of 3 Ω. The equivalent delta arrangement
will have each resistance of values
[a]
a)9 Ω b) 6 Ω c) 3 Ω d)1 Ω
9. The capacitance of parallel path capacitor is not affected by
[d]
a) area of plates b) plate thickness c) distance between the plates d) nature of dielectric
10. Three resistors of 4Ω, 6 Ω and 8 Ω are connected in parallel. In which resistor power
Spent is maximum?
[a]
a)4 Ω b) 6 Ω c)8 Ω d)equally in the resistors
11. In mesh current method of network analysis, the independent variables is
a)node current b) mesh current c) node voltage d) none
[b]
12. Identify the passive element among the following
a. Voltage source b. current source c.inductor d. transistor
13. How much energy is stored by a 0.05μF capacitor with a voltage of 1000V?
a.0.025J b. 0.05J c. 5J d. 100J
14. Mesh Analysis is based on ………
a. KCL b.KVL c. Both d. None
15. The nodal method of circuit analysis is based on
a. KVL + ohms law b. KCL + ohms law c. KVL + KCL d. KVL + ohms law +KCL
16. The curve representing Ohm’s law is _________
(a) Sine function (b) Linear (c) Parabola (d) Hyperbola
17. The ratio of voltage and current in a closed circuit is ________
(a) Remains Constant (b) Varies (c) Increases (d) Falls
[c]
[b]
[a]
[b]
[b]
[a]
18. Resistance of human body is about _____Ω
[c] (a)
10 (b) 100 (c) 1K (d) Zero
19. In case of delta connected circuit, when one resistor is opened then the power will be reduced
by 1/3.
20. In series circuit current acts as a reference and parallel circuit voltage acts as reference.
21. Inductor acts as a short circuit to DC
22. Ideal sources is nothing but sources without losses
23. Electromotive force (EMF) is the force that causes a current to flow.
24. The energy stored in a capacitor is 0.5*c*v2
25. Capacitance is a measure of the ability of a capacitor to store an electric charge.
OBJECTIVE (UNIT-II)
1. When two alternating waves attain their peak values simultaneously the waves are [b]
a) In quadrature b) in phase c) out of phase by 180o d) none
2. Static shunt capacitors are employed to improve power factor. The power factor is
improved because leading current
[c]
a)Reduces heat loss b) increase lagging current c) neutralizes the lagging current d) none
3. The power consumed in a pure inductive circuit is Zero
4. The magnitude of current in a parallel RL circuit, when the applied voltage has an
RMS value of V volt is given by V√(1/R2 + 1/XL2))
5. Form factor for a triangular waveform is Vm/√3
6. The relation between Real power (P), Reactive Power (Q) and Apparent Power(S) is S2= P2+ Q2
7. Power factor of an AC circuit is defined as Reactive power / Apparent power
8. An ac current is given as i(t)=10+10 sin(314t), its Average value is 10
9. The magnitude & phase of current vector is depend on the values of R, L, C, F
10. Unit of susceptance is Siemens
11. Phasor diagram is used to represent the relation between two (or) more Sine waves
of same frequency
12. Ratio of RMS value to the Average value is called as form factor
13. The phase angle of series RLC circuit at resonance is 0
14. The phasor diagram for alternating quantities can be drawn if they have Sinusoidal wave
15. The form factor for DC supply voltage is always unity
16. In an R-L series circuit the power factor is [B ] (A) Leading (B) lagging (C) Zero (D) Unity
17. In a purely inductive circuit _________ power is Zero. [ D]
(A) Apparent (B) Reactive (C) Inductive (D) True
18. Electrical power converted into heat due to flow of an alternating current through an
ohmic resistance is called the [B]
(A) Heating power (B)True Power (C)Reactive Power (D)Apparent Power
19. If the waveforms of voltage and current are sinusoidal, the true power is calculated by
the formula [b]
a)P = VI b) P = VI CosΦ c) P = VI SinΦ d) P = (V2 /I)cosΦ
20. The phase angle of series RLC circuit at resonance is 0
OBJECTIVE (UNIT-III)
1. The band width of series RLC resonating circuit is represented by
[a]
a)R/2πL b) C/ 2πL c) C/2πR d) L/ 2πR
2. If the waveforms of voltage and current are sinusoidal, the true power is calculated by
the formula
[b]
a)P = VI b) P = VI CosΦ c) P = VI SinΦ d) P = (V2/I)cosΦ
3. In an inductive circuit, when the frequency of applied voltage is increased, the
Current will decrease
4. Under resonance conditions XL= Xc and f=1/2π√ (L/C)
5. Quality factor Qo (in terms of C &R) =WoCR
6. The expression of frequency at which the voltage across capacitance is maximum f c=
1/2π√(1/LC-R2/ 2C2)
7. Q-factor of a resonant circuit id defined as 2πX(Maximum Stored Energy/Energy
dissipated per cycle)
8. Resonant frequency ‘fr of a series R-L-C circuit is related to half power frequencies fa and
f2 as fr =( fa f2)0.5
9. If the Band width is low the selectivity will be high
10. The maximum possible mutual inductance of two inductively coupled coils with self
inductances L1=25mH and L2=100mH is given by
(a)125mH
(b)75mH
(c)50mH
(d)15mH
11. Which of the following does not change in a transformer?
(a) Frequency
(b) Voltage and Current
(c) Current
(d) Voltage
12. Voltmeter is used to measure the between two points of a circuit.
(a) Power loss
(b) Potential difference
(c) Current
(d) Energy
13. Power in AC circuits is given by
(a) VI tan Φ
(b) VI
(c) VI sin Φ
(d) VI cos Φ
14. Average emf induced per turn is given by
(a) 4.44f Φm volts
(b) 4.44f N Φm volts
(c) 4f Φm volts
(d) zero volts
15. A coil of resistance 100 and 100 μH is connected in series with a 100 PF is connected to a 10V,
variable frequency supply. What is the Q factor of the circuit?
(a) 1
(b) 100
(c) 10
(d) 0.1
16. Two coils connected in series have an equivalent inductance of 3H when connected in aiding. If
the self inductance of the first coil is 1H, what is the self inductance of the second coil?(Assume
M=0.5H)
(a)1H
(b)2H
(c)3H
(d)4H
17. Mutual inductance is a property associated with
(a) only one coil
(b)two or more coils
(c)two or more coils with magnetic coupling (d)none
18. The case for which the coefficient of coupling K=1 is called perfect coupling
(a)true
(b)false
19. Mutually induced voltage is present in present independently of,and in addition to,the volate
due to self induction
(a)true
(b)false
20. The maximum value of the coefficient of coupling is
(a)100%
(b)50%
(c)more than 100%
(d)90%
OBJECTIVE (UNIT-IV)
1. The tree of a graph containing N nodes has ____________ branches
A) N+1 B) N C) N-1 D) N/2
2. Cutset matrix is generally used to find_______________
A) Branch voltages B) Branch currents C) Branch impedance D) None
3. If there are b branches and n nodes the number of equations will be
A) n-1 B) b C) b-n D) b-n+1
4. A closed path made by several branches of the network is known as
A) Circuit B) Loop C) Junction D) Branch
5. The number of branches in a tree is ---- the number of in a graph
A) Less than B) more than C) equal to D) none
6. A tree has
A) A closed path B) no closed paths C) both D) none
7. The tie-set schedule gives the relation between
A) branch and link currents
B) branch voltages and link currents
C) branch currents and link voltages D) none of the above
8. The Cut-set schedule gives the relation between
A) branch and link currents
B) branch voltages and tree branch voltages
C) branch voltages and link voltages D) branch and tree branch currents
9. A network has 10 nodes and 17 branches .The number of different node pair
voltages would be
A) 7 B) 9 C) 45 D) 10
10. What type of identity matrices are formed in a Cutset and tie set matrices?
A) twig, link B) link, link C) link, twig D) twig, twig
11.
12.
13.
14.
[C]
[A]
[D]
[B]
[A]
[B]
[C]
[B]
[C]
[A]
Oriented graph is also called as Directed graph
The dual element of Inductance (L) is Capacitance (C)
The dual element of capacitance (C) is Inductance (L)
The dual element of Resistance(R) is Conductance (G)
15. If the network graph has 9 branches, 6 nodes and 4 independent loops, then the dual graph
will have
(a)b=9 nt=5
(b), l=5 b=6, nt=5,
(c)l=5 b=5, nt=5, l=5 (d)b=9, nt=6, l=4
16 The number of twigs (or) branches in any tree will be equal to the number of
(a)(Loops-1) (b) (Loops+1) (c) (Nodes+1) (d) (nodes-1)
17. For a connected planar graph of 'v' vertices and 'e' edges, the number of meshes is
(a)(v-1)
(b) (e-v)
(c) (e-v+1)
(d) (e-v-1)
18. To any tree of a graph, addition of a link result in a
(a)Loop
(b) Tie-set
(c) Node
(d) Branch
(c) Tree branch
(d) Tie-set
19. The duality of cut-set is
(a)Off-set
(b) Link-set
20. If a graph is drawn on a plane, and if two branches cross each other it is called a _ _ _ _ _ _ _ _
_ _ _ _ _ _ _ graph
(a)Link(b) Loop
(c) Planar
(d) Non-Planar
OBJECTIVE (UNIT-V)
1. The superposition theorem is essentially based on the concept of
A) Reciprocity B) Linearity C) Duality D) Non-linearity
[B]
2. The theorem that enables a number of voltage (or current) sources to be combined directly
into a single voltage( or current) sources is_______________
[C]
A) Compensation B) Reciprocity C) Millman’s D) Maxwell’s theorem
3. Millman’s theorem yields equivalent
A) Impedance B) Current source C) Voltage source D) Voltage or current source
[D]
4. The superposition theorem requires as many circuits to be solved, as the number
of ______
Nodes B) Sources C) Meshes D) Nodes, Sources and Meshes.
[B] A)
5. Thevenins’s resistance Rth is determined ___________
[B]
A) By short circuiting given two terminals B) By replacing voltage sources
With their internal resistance C) Between same open terminals for Vth
D) Between the two open terminals
6. The maximum efficiency of power transfer to load is
A) 25% B) 50% C) 75% D) 100%
[B]
7. Tellegen’s theorem is applicable to
A) Linear networks only
C) Both linear and non-linear networks
[C]
B) Non-linear networks only
D) none of the above.
8. The theorem that enables a number of voltage sources to be combined directly into
a single voltage (or current) source is the _________ theorem.
A) Compensation B) Reciprocity C) Millman’s D) Maxwell’s
9.
[C]
An ideal voltage source & ideal current source are connected in parallel. This circuit has [A]
A) Norton’s equivalent but not Thevenins’s equivalent B) Thevenins’s equivalent but not
Norton’s equivalent C) Both the Thevenins’s equivalent and Norton’s equivalent
D) Neither Thevenins’s nor Norton’s equivalent
10. Reciprocity theorem is valid for
A) All linear networks B) all active networks C) all linear, passive, and bilateral
D) All linear and passive
11. Which of the following theorem is applicable for both linear and non linear circuits
A) Superposition B) Thevenins’s C) Norton’s theorem D) none of these
[C]
[D]
12. Maximum power transfer theorem can be applied to both ac and dc circuits.
13. When the superposition theorem is applied to any circuit, the depend voltage source in
that circuit is always active
14.
While determining R TH Thevenins’s and Norton’s equivalent all independent sources
are made dead
15.
A Norton equivalent of an AC circuit is represented by a Current source in parallel
with an impedance.
16.
The ratio of E/I in reciprocity theorem is called transfer resistance.
17.
In Tellegen’s theorem the sum of instaneous powers for n branches in a network is
always Zero.
18.
If RI=RL is for maximum power transfer, then maximum power transferred is given by
E2 / 4 Ri2
19.
While calculating Rth, constant current sources in the circuit are replaced by Open
20.
Two identical 3A, 1ohm batteries are connected in parallel with like polarities to
like. The Norton equivalent circuit of combination is 6 Amp. & 0.5 ohm.
21.
A 12V source with an internal resistance of 1.2ohm is connected across a wire wound
resistor. Maximum power is dissipated in the resistor when its resistance is equal to
1.2 ohm.
22.
Compensation theorem is applicable to linear and non-linear networks