Monday 23 June 2014

NETWORK ANALYSIS AND SYNTHESIS QUESTION1


1. Who proposed the law of electromagnetic induction?
a. Coulomb
b. Faraday
c. Ohm
d. Kirchoff
2. The resistance R offered by a conductor is
a. Inversely proportional to its length
b. Directly proportional to its length
c. Directly proportional to the cross-sectional area of the conductor
d. Independent of temperature of the conductor
3. The minimum number of watt-meters required for measuring power in a 3-phase unbalanced star-connected load is
a. 1
b. 2
c. 3
d. 5
4. What is the power in watts if energy equal to 75 j is used in 2 seconds?
a. 0.027W
b. 37.5W
c. 77W
d. 150W
5. Which one of the following statements is false with respect to an inductor?
a. It is also called as non-dissipative passive element
b. It stores finite amount of energy even if the voltage across it is zero
c. The current doesn’t change abruptly in a fixed inductor
d. It acts as open circuit to DC
6. If there are X number of branches and Y number of nodes including the reference node, then the number of linearly independent mesh M is given by
a. M=X+(Y+1)
b. M=X-(Y+1)
c. M=Y+(X-1)
d. M=Y-(X-1)
7. More voltage is delivered to the load when
a. Load resistance is low as compared to the resistance of the source
b. Load resistance is high as compared to the resistance of the source
c. Load resistance is same as compared to the resistance of the source
d. None
8. When the frequency of the applied voltage in a series RC circuit is increased, its capacitive reactance
a. Increases
b. Decreases
c. Remains same
d. Equals to zero
9. The circuit is said to be in resonance only if
a. XLXC
c. XL=XC
d. XL=0
10. The current magnification commonly occurs in
a. Series resonant circuit
b. Parallel resonant circuit
c. Series-parallel resonant circuit
d. None 
11. A resistor of 2 ohms is connected in series with a combination of 3 ohms in parallel. The total resistance is given by
a. 2.5ohms
b. 3.0ohms
c. 3.5ohms
d. 8.0ohms
12. The name given to the property of material, which opposes the creation of magnetic flux is
a. Resistance
b. Conductance
c. Reactance
d. Reluctance
13. The greater the resistance of a tuned circuit, ------ is the value of Q of the circuit
a. Greater
b. Lesser
c. Greater or lesser
d. None
14. If current through a resistor 10 MΩ is halved, the wattage developed by it would be
a. Halved
b. Quadrupled
c. Cut to one-fourth
d. Doubled
15. In common-emitter amplifier, the input and output signals are
a. Out of phase
b. In phase
c. 360 out of phase
d. None

16. The second is now defined as reciprocal of 31, 556, 9747 of the tropical year
a. 1890
b. 1900
c. 1906
d. 1915
17. The resistivity of the metallic conductors 
a. Remains linear with rise in temperature
b. Remains non-linear with rise in temperature
c. Remains linear at low temperatures and then becomes non-linear at high temperatures
d. Remains linear at significant range of temperature and then becomes non-linear at very low and high temperatures
18. If 70 joules of energy is available for every 35 C of change, then voltage developed is equal to 
a. 2.00V
b. 0.429V
c. 105V
d. 35V
19. An example for bilateral element is
a. Silicon diodes
b. Vacuum diodes
c. Metal rectifiers
d. Elements made of high conductivity properties
20. A capacitor energy in the form of
a. Charges
b. Bits
c. Energy field
d. Magnetic field
21. Superposition theorem is valid for
a. Computing voltage responses
b. Computing current responses
c. Computing power responses
d. All
22. Maximum current is transferred to the load when
a. Load resistance is low as compared to the resistance of the source
b. Load resistance is high as compared to the resistance of the source
c. Load resistance is same as compared to the resistance of the source
d. None
23. In the case of sinusoidal source, the power factor is
a. Sine of the phase angle between voltage and current 
b. Cosine of the phase angle between voltage and current 
c. Tangent of the phase angle between voltage and current
d. Secant of the phase angle between voltage and current
24. A circuit is said to be in resonance only if
a. XL< Xc b. XL> Xc
c. XL= Xc
d. XL= Xc=0
25. The total reactance of a series PIL circuit at resonance is
a. Equal to XL
b. Equal to Xc
c. Equal to R
d. Equal to zero
26. The resistance of a low coil is 25ohms when connected in series and 6ohms when connected in parallel, and then the individual resistance of two coils is
a. 10Ω, 5Ω
b. 10Ω, 15Ω
c. 12Ω, 16Ω
d. 7.5Ω, 3Ω
27. Match the following

(P) Series feedback connection (1) increases input impedance
(Q) Shunt feedback connection (2) decreases the input impedance
(R) Current feedback connection (3) increases the output impedance
(S) Voltage feedback connection (4) decreases the output impedance
a. P-1, Q-2, R-3, S-4
b. P-4, Q-2, R-3, S-1
c. P-1, Q-3, R-4, S-2
d. P-1, Q-2, R-4, S-3
28. Power amplifier in practice
a. Amplifies power
b. Is DC to AC power converter
c. Amplifies voltage
d. Amplifies current
29. The capacitance value 1µµF is equal to 
a. 10^-3 F
b. 10^-6 F
c. 10^-9 F
d. 10^-12F
30. Consider the statements with respect to common-base amplifier.
Statement 1: voltage gain is more than unity
Statement 2: current gain is less than unity
Which of the following is valid?

a. Statement 1 only
b. Statement 2 only
c. Both Statements 1&2 
d. Either Statement 1 or 2
31. Kirchhoff’s voltage law is applicable to 
a. DC circuits only
b. AC circuits only
c. AC and DC circuits
d. High resistance DC circuits only
32. The direction of the magnetic field around a current carrying inductor can be determined by
a. Cork screw rule
b. Right hand rule
c. Left hand rule
d. Either a or b
33. Six coulombs of charge flow past a given point in a conducting wire in 2 seconds, the ampere of current is given by
a. I=(6/2)A
b. I=(6*2)A
c. I=(2/6)A
d. I=(6-2)A
34. The tendency of alternating current to concentrate near the surface of a conductor is known as
a. Johnson’s effect
b. Corona effect
c. Skin effect
d. Kelvin’s effect
35. A pure capacitor is a 
a. Dissipative passive element
b. Non-dissipative passive element
c. Dissipative active element
d. Non-dissipative active element
36. The Tellegan’s theorem is valid for any lumped network, which may be
a. Linear or non-linear
b. Passive or active
c. Time-varying or time-invariant
d. All
37. The statement “In a arbitrary lumped network, the algebraic sum of the powers in all branches at any instant is zero “ belongs to which theorem?
a. Reciprocity theorem
b. Thevenin’s theorem
c. Tellegen’s theorem
d. Millmans’s theorem
38. For diode, reverse recovery time is defined as the time between the instant diode current becomes zero and the instant reverse current decays to
a. Zero
b. 10% of reverse peak current IRM
c. 25% of reverse peak current IRM
d. 15% of reverse peak current IRM
39. |Z| = sqrt(R*R + (WL-1/Wc) ) is the impedance of
a. Series RL circuit
b. Series RC circuit
c. Series RLC circuit
d. WL/Wc
40. A resitance of 10 ohm is connected in a branch of a network. The current flow through that branch is found to be 5 A. If the 10 ohm is replaced by 20 ohm resistor, than the current in the branch
a. Will be less than 5A
b. Will be greater than 5A
c. Wil be less than or more than 5A
d. Will be equal to 5A
41. As per KVL, the algebraic sum of all voltage drop and emf’s in any closed loop or mesh of network is always
a. Zero
b. Positive
c. Negative
d. Depending on the emf
42. The voltage gain of an amplifier is 100. When negative feedback is introduced with a feedback factor equal to 0.03, its gain will be
a. 20
b. 25
c. 30
d. 35
43. Non-linear distortion is otherwise known as
a. Amplitude distortion
b. Frequency distortion
c. Phase distortion
d. Signal noise distortion
44. Which one of the following relationships is incorrect?
a. I=V/R
b. V=IR
c. R=V/I
d. V=I/R
45. When a conductor is subjected to a rise in temperature then
a. Its resistance increases
b. Its specific resistance increases
c. Its resistivity increases
d. All
46. The maximum value of an alternating emf is given by the coefficient of
a. The sine of the time angle
b. The cosine of the time angle
c. The tangent of the time angle
d. The secant of the time angle
47. Which one of the following is an active element
a. Resistor
b. Capacitor
c. Inductor
d. Vacuum tube
48. If the AC supply frequency is increased , then the loss due to the skin effect 
a. Decreases
b. Increases
c. Remains unchanged
d. Does not exist at all
49. Which of the following is incident if the node is a terminal of a branch?
a. Node
b. Branch
c. Both node and branch
d. Either node or branch
50. One hertz is equal to 
a. Two cycles per minute
b. One cycle per minute
c. Two cycles per second
d. One cycle per second
51. A sinewave has a peak value of 15V; the RMS value is given as 
a. 7.50 V
b. 8.48 V
c. 10.61 V
d. 15.00V
52. Match the following items:
(A) Purely resistive circuit (1) phase angle between V & I is zero
(B) RC circuit (2) leading power factor
(C) RL circuit (3) lagging power factor
a. A- 1, B-3, C-2
b. A-2, B-3, C-1
c. A-1, B-2, C-3
d. A-3, B-2, C-1
53. At resonant frequency , when the capacitive reactance is equal to inductive reactance, the 
a. Impedance is zero
b. Impedance is infinity
c. Impedance is minimum
d. Impedance is maximum
54. If a conducting wire has the smaller length and largest cross- section then
a. Low is the resistanc value
b. High is the resistance value
c. Low or high is the resistive value
d. No change in the resistance value
55. The resistance of wire is 2 ohms, if the cross section area of the wire is reduced to half, keeping the length constant, the resistance will be
a. 8 ohms
b. 4 ohms
c. 2 ohms
d. 1 ohm
56. The voltage gain of an amplifier is 120 when negative feedback is introduced then its gain will be
a. Equal to 120
b. Les than 120
c. Greater than 120
d. Less than or equal to 120
57. In class A amplifier, the Q popint is approximately
a. At the edge of AC load
b. At the centre of AC load line
c. Away from AC load line
d. At the origin of AC load line
58. Work is same as
a. Energy
b. Power
c. Both a & b
d. None
59. In a noiseless amplifier, the noise level measured is found to be
a. 3 db
b. 2 db
c. 1 db
d. 0 db
60. The law that explains the generation of heat due to the flow of current through a conductor is
a. Ohm’s law
b. Faraday’s law
c. Kirchhoff’s law
d. Joules law
61. The AC supply of a building is given by 230 V/50 Hz. The maximum voltage is given by
a. 361.08
b. 325.27V
c. 311.08V
d. 230V
62. Match the following with its correspondence dual 
(P) Current I. open circuit
(Q) Short circuit II. Capacitance
(R) Inductance III. Node potential
(S) mesh current IV. Voltage

a. P-IV, Q-I, R-II, S-III
b. P-I, Q-II, R-III, S-IV
c. P-IV, Q-III, R-II, S-I
d. P-III, Q-II, R-I, S-IV
63. The unit of resistance and conductance is/are
a. Ohms & mho respectively
b. Ohms
c. Mho
d. Watts
64. With reference to the below given figure, the degree of node 3 is


Fig:
a. One
b. Two
c. Three
d. Four
65. ------------------- is the measure of the heating effect of sine wave.
a. Instantaneous value
b. Average value
c. Peak to peak value
d. RMS value
66. When the frequency of a sine wave voltage applied across an inductor is increased, the current 
a. Decreases
b. Increases
c. Remains the same
d. Increases proportionately
67. The reactive power is expressed in
a. Volt reactive
b. Volt ampere
c. Volt-ampere reactive
d. Volts
68. The bandwidth of any system is the range of frequency for which the current of output voltage is equal to ----------- of its value at the resonant frequency.
a. 30.3%
b. 20.2%
c. 60.6%
d. 70.7%
69. To increase the resistance of a conducting wire
a. Increase the length & decrease the area of conducting wire
b. Decrease the length & increase the area of conducting wire
c. Decrease the area & increase the length of conducting wire
d. Decrease the length & the area of conducting wire
70. If 10 resistors each of 5 ohm are connected in series, the effective resistance is given by
a. 2 ohm
b. 5 ohm
c. 25 ohm
d. 50 ohm
71. The frequency of oscillation of phase shift oscillator is give by
a. 1/2π RC
b. 1/2π LC
c. 1/(2π/ RC)
d. 1/π RC
72. The practical efficiency fig. for class-A amplifier is
a. Less than 25%
b. Greater than 25%
c. Equal to 25%
d. Exactly 98%
73. To double the flow of current in a circuit of constant resistance, the applied voltage must be
a. Doubled
b. Halved
c. Quadrupled
d. Maintained constant
74. Which amplifier can be employed as frequency multipliers?
a. Class-A
b. Class-B
c. Class-AB
d. Class-C
75. If a metallic wire is trenched to its double the original length, then the new resistance will be
a. Same as its original length
b. Twice that of its original resistance
c. Thrice that of its original resistance
d. Four times that of its original resistance
76. The instantaneous value of alternating current is given by i=40.36 sin 180t, then the maximum alternating current is given by
a. 0
b. Infinity
c. 20.13
d. 40.36
77. KVL states that the algebraic sum of voltages around a closed path loop is zero. However, if voltages are considered as phasors the KVL implies (pick wrong answer)
a. Algebraic sum of only real parts of voltage around a closed loop is zero
b. Algebraic sum of only Imaginary parts of voltage around a closed loop is zero
c. Algebraic sum of only real and imaginary parts is separately zero
d. Algebraic sum of the magnitudes of voltages around the loop is zero
78. A linear network is one which satisfies 
a. Principle of superposition
b. Principle of homogeneity
c. Principle of additivity
d. All
79. If a tree has N number of nodes, then it has
a. N number of branches
b. N+1 number of branches
c. N-1 number of branches
d. 2n number of branches
80. A pure inductor has an impedance phase value equal to
a. ώ/L
b. L/ώ
c. ώL
d. ώ^2 *L
81. In a pure resistor, the current and voltage are
a. 180 out of phase
b. 90 out of phase
c. 260 out of phase
d. In phase
82. Poor dissipation in an RC circuit is mainly due to 
a. Resistor
b. Capacitor
c. Both R & C
d. None
83. The maximum voltage across the capacitor occurs --------- the resonant frequency.
a. Below
b. Below and above
c. Above
d. None
84. To decrease the resistance of a conducting wire
a. Increase the length and decrease the area of conducting wire
b. Decrease the length and increase the area of cross section
c. Decrease the length and increase the area of conducting wire
d. Decrease the length and the area of conducting wire.
85. The symbol j represents
a. Clock wise rotation of a phasor 90
b. Clockwise rotation of a phasor 180
c. Anti-clockwise rotation of a phasor 90
d. Anti-clockwise rotation of a phasor 180
86. The natural frequency of a crystal is given as
a. F=kt
b. F=k/t
c. F=sqrt(kt)
d. F=k+t
87. The dB is
a. Unit of power
b. Unit of power change
c. Unit of sound
d. Unit of frequency
88. The voltage rating of a cell is
a. Voltage produced when load is connected 
b. Equal to the short-circuit voltage
c. Equal to the open circuit voltage
d. Voltage produced when 1 Kohm of resistance is connected
89. When two amplifiers of identical bandwidth are cascaded, the overall bandwidth will be
a. Doubled
b. Increased
c. Decreased
d. Unaffected
90. The sign of voltage drop observed across the resistor
a. Depends on direction of current flow through it and polarity of emf source
b. Depends on direction of current flow through it and independent of polarity of emf source
c. Independent of both current flow through it and polarity of emf source
d. Independent of current flow through it and dependent on the polarity of the emf source
91. The relationship I=V/R holds good for
a. Dc circuit only
b. Ac circuit only
c. Both AC and DC
d. None
92. Consider the statements
i) All networks have duals
ii) A tree graph must have atleast one closed path
Which of the following is true?
a. i only
b. ii only
c. both
d. either i 0r ii
93. A non-linear network is one which does not satisfy 
a. Principle of superposition
b. Principle of homogeneity
c. Principle of additivity
d. All 
94. The solution of a network can be determined by applying
a. Mesh analysis
b. Nodal analysis
c. Both mesh and nodal analyses
d. None
95. In a pure capacitor, the current ----------- voltage by-----
a. Leads,90
b. Lags, 90
c. Leads, 180
d. Lags, 180
96. The form factor of DC voltage is
a. 0.5
b. 1
c. 0
d. Infinity
97. Norton’s equivalent form in any complex impedance circuit consists of
a. An equivalent current source in parallel with an equivalent resistance
b. An equivalent voltage source in series with an equivalent resistance
c. An equivalent current source in parallel with an equivalent impedance
d. An equivalent voltage source in parallel with an equivalent impedance
98. In any resonant circuit, the narrower the bandwidth, ------- is the sensitivity
a. Lower
b. Higher
c. Poorer
d. None
99. With reference to ohms law, which one of the is incorrect?
a. dv= Rdi
b. Tungsten follows ohms law
c. Zener diode follows ohms law
d. Voltage regulator tubes do not follow ohms law
100. Beside hydrogen other materials which posses the diamagnetic characteristics are
a. Mercury and gold
b. Iron and aluminum
c. Chromium and bismuth
d. Silver and copper
101. If the applied frequency decreases than the resonant frequency, the value of
a. XL increases and Xc decreases
b. XL decreases and Xc increases
c. Both XL and Xc increases
d. Both XL and Xc decreases

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