Essential Objective Questions On Network Theorems For Gate Preparation
1.”In any network containing more than one sources of e.m.f. the current in any branch is the algebraic sum of a number of individual fictitious currents (the number being equal to the number of sources of e.m.f.), each of which is due to separate action of each source of e.m.f., taken in order, when the remaining sources of e.m.f. are replaced by conductors, the resistances of which are equal to the internal resistances of the respective sources”. The above statement is associated with
Thevenin’s theorem
Norton’s theorem
Superposition theorem
None of the above
ANSWER : : Superposition theorem
2.The concept on which Superposition theorem is based is
reciprocity
duality
non-linearity
linearity
ANSWER : : linearity
3.Kirchhoff s law is applicable to
passive networks only
a.c. circuits only
d.c. circuits only
both a.c. as well d.c. circuits
ANSWER : : both a.c. as well d.c. circuits
4.The resistance LM will be
6.66 Q
12 Q
18Q
20Q
ANSWER : : 6.66 Q
5.”In any linear bilateral network, if a source of e.m.f. E in any branch produces a current I in any other branch, then same e.m.f. acting in the second branch would produce the same current / in the first branch”. The above statement is associated with
compensation theorem
superposition theorem
reciprocity theorem
none of the above
ANSWER : : reciprocity theorem
6.”Any number of current sources in parallel may be replaced by a single current source whose current is the algebraic sum of individual source currents and source resistance is the parallel combination of individual source resistances”. The above statement is associated with
Thevenin’s theorem
Millman’s theorem
Maximum power transfer theorem
None of the above
ANSWER : : Millman’s theorem
7.Kirchhoff s law is not applicable to circuits with
lumped parameters
passive elements
distributed parameters
non-linear resistances
ANSWER : : distributed parameters
8.Thevenin resistance Rth is found
by removing voltage sources along with their internal resistances
by short-circuiting the given two terminals
between any two ‘open’ terminals
between same open terminals as for Etk
ANSWER : : between same open terminals as for Etk
9.Which of the following is non-linear circuit parameter ?
Inductance
Condenser
Wire wound resistor
Transistor
ANSWER : : Inductance
10.If resistance across LM in Fig. 2.30 is 15 ohms, the value of R is
10 Q
20 Q
30 Q
40 Q
ANSWER : : 30 Q
11.An ideal voltage source should have
large value of e.m.f.
small value of e.m.f.
zero source resistance
infinite source resistance
ANSWER : : zero source resistance
12.For maximum transfer of power, internal resistance of the source should be
equal to load resistance
less than the load resistance
greater than the load resistance
none of the above
ANSWER : : equal to load resistance
13.For high efficiency of transfer of power, internal resistance of the source should be
equal to the load resistance
less than the load resistance
more than the load resistance
none of the above
ANSWER : : less than the load resistance
14.Kirchhoff s voltage law applies to circuits with
nonlinear elements only
linear elements only
linear, non-linear, active and passive elements
linear, non-linear, active, passive, time varying as wells as time-in-variant elements
ANSWER : : linear, non-linear, active, passive, time varying as wells as time-in-variant elements
15.According to Kirchhoffs voltage law, the algebraic sum of all IR drops and e.m.fs. in any closed loop of a network is always
negative
positive
determined by battery e.m.fs.
zero
ANSWER : : zero
16.Kirchhoffs voltage law is related to
junction currents
battery e.m.fs.
IR drops
both (b) and (c)
ANSWER : : both (b) and (c)
17.Kirchhoffs current law is applicable to only
junction in a network
closed loops in a network
electric circuits
electronic circuits
ANSWER : : junction in a network
18.Efficiency of power transfer when maximum transfer of power c xurs is
100%
80%
75%
50%
ANSWER : : 50%
19.Superposition theorem can be applied only to circuits having
resistive elements
passive elements
non-linear elements
linear bilateral elements
ANSWER : : linear bilateral elements
20.”Maximum power output is obtained from a network when the load resistance is equal to the output resistance of the network as seen from the terminals of the load”. The above statement is associated with
Millman’s theorem
Thevenin’s theorem
Superposition theorem
Maximum power transfer theorem
ANSWER : : Maximum power transfer theorem
21.A capacitor is generally a
bilateral and active component
active, passive, linear and nonlinear component
linear and bilateral component
non-linear and active component
ANSWER : : linear and bilateral component
22.If the energy is supplied from a source, whose resistance is 1 ohm, to a load of 100 ohms the source will be
a voltage source
a current source
both of above
none of the above
ANSWER : : a voltage source
23.For a voltage source
terminal voltage is always lower than source e.m.f.
terminal voltage cannot be higher than source e.m.f.
the source e.m.f. and terminal voltage are equal
terminal voltage cannot be higher than source e.m.f.
ANSWER : o determine the polarity of the voltage drop across a resistor, it is necessary to know
24.A terminal where three on more branches meet is known as
node
terminus
combination
anode
ANSWER : : node
25.The number of independent equations to solve a network is equal to
the number of chords
the number of branches
sum of the number of branches and chords
sum of number of branches, chords and nodes
ANSWER : : the number of chords
26.An ideal voltage source has
zero internal resistance
open circuit voltage equal to the voltage on full load
terminal voltage in proportion to current
terminal voltage in proportion to load
ANSWER : : zero internal resistance
27.A passive network is one which contains
only variable resistances
only some sources of e.m.f. in it
only two sources of e.m.f. in it
no source of e.m.f. in it
ANSWER : : no source of e.m.f. in it
28.The superposition theorem is applicable to
linear, non-linear and time variant responses
linear and non-linear resistors only
linear responses only
none of the above
ANSWER : : linear responses only
29.A closed path made by several branches of the network is known as
branch
loop
circuit
junction
ANSWER : : loop
30.Which of the following is the passive element ?
Capacitance
Ideal current source
Ideal voltage source
All of the above
ANSWER : : Capacitance
31.Millman’s theorem yields
equivalent resistance
equivalent impedance
equivalent voltage source
equivalent voltage or current source
ANSWER : : equivalent voltage or current source
32.Which of the following is a bilateral element ?
Constant current source
Constant voltage source
Capacitance
None of the above
ANSWER : : Capacitance
33.The circuit has resistors, capacitors and semi-conductor diodes. The circuit will be known as
non-linear circuit
linear circuit
bilateral circuit
none of the above
ANSWER : : non-linear circuit
34.A star circuit has element of resistance R/2. The equivalent delta elements will be
R/6
fi?
2R
4R
ANSWER : : fi?
35.A delta circuit has each element of value R/2. The equivalent elements of star circuit with be
RIG
R/3
2R
3R
ANSWER : : RIG
36.In a series parallel circuit, any two resistances in the same current path must be in
series with each other
parallel with each other
series with the voltage source.’
parallel with the voltage source
ANSWER : : series with each other
37.Choose the incorrect statement.
A branch formed by the parallel connection of any resistor R and open circuit has the characteristic of an open circuit.
A branch formed by the parallel connection of any resistor R and a short circuit has the characteristic of a short circuit.
A branch formed by the series connection of any resistor R and an open circuit has the characteristic of an open circuit.
A branch formed by the series connection of any resistor R and a short circuit has the characteristic of resistor R.
ANSWER : : A branch formed by the parallel connection of any resistor R and open circuit has the characteristic of an open circuit.
38.Application of Norton’s theorem to a circuit yields
equivalent current source and impedance in series
equivalent current source and impedance in parallel
equivalent impedance
equivalent current source
ANSWER : : equivalent current source and impedance in series
39.The superposition theorem requires as many circuits to be solved as there are
sources, nodes and meshes
sources and nodes
sources
nodes
ANSWER : : sources
40.A non-linear network does not satisfy
superposition condition
homogeneity condition
both homogeneity as well as superposition condition
homogeneity, superposition and associative condition
ANSWER : : both homogeneity as well as superposition condition
41.A network which contains one or more than one source of e.m.f. is known as
linear network
non-linear network
passive network
active network
ANSWER : : passive network
42.While calculating Rth in Thevenin’s theorem and Norton equivalent
all independent sources are made dead
only current sources are made dead
only voltage sources are made dead
all voltage and current sources are made dead
ANSWER : : all independent sources are made dead
43.Between the branch voltages of a loop the Kirchhoff s voltage law imposes
non-linear constraints
linear constraints
no constraints
none of the above
ANSWER : : linear constraints
44.In Thevenin’s theorem, to find Z
all independent current sources are short circuited and independent voltage sources are open circuited
all independent voltage sources are open circuited and all independent current sources are short circuited
all independent voltage and current sources are short circuited
all independent voltage sources are short circuited and all independent current sources are open circuited
ANSWER : : all independent voltage sources are short circuited and all independent current sources are open circuited
45.A linear resistor having 0 < R < �o is a
current controlled resistor
voltage controlled resistor
both current controlled and voltage controlled resistor
none of the above
ANSWER : : both current controlled and voltage controlled resistor
46.The superposition theorem is applicable to
voltage only
current “only
both current and voltage
current voltage and power
ANSWER : : current voltage and power