APTRANSCO/APGENCO ELECTRICAL & ELECTRONICS/TELECOM MODEL QUESTIONS/STUDY MATERIAL
Here you can find study material for APGENCO,APTRANSCO,BHEL,NTPS,GATE & other government examinations for both electrical & electronics streams in the form of model questions along with solutions and explanations.More questions will be updated soon….keep visiting
ELECTRIC CIRCUITS/NETWORK ANALYSIS-STUDY MATERIAL & MODEL QUESTIONS
To calculate Thevenin’s equivalent impedance value in a circuit, all independent voltage sources are shorted while all independent current sources are opened. Q.2 A 26 dBm output in watts equals to (A) 2.4W. (B) 0.26W. (C) 0.156W. (D) 0.4W. Ans: A A 26dBm output in watts equals to 0.4 W because
10*log10(400MW/1MW) = 26DB Q.3 The Characteristic Impedance of a low pass filter in attenuation Band is (A) Purely imaginary. (B) Zero. (C) Complex quantity. (D) Real value. Ans: A The characteristic impedance of a low pass filter in attenuation band is purely imaginary. Q.4 The real part of the propagation constant shows: (A) Variation of voltage and current on basic unit. (B) Variation of phase shift/position of voltage. (C) Reduction in voltage, current values of signal amplitude. (D) Reduction of only voltage amplitude. Ans: C
The real part of the propagation constant shows reduction in voltage, current values of signal amplitude. Q.5 The purpose of an Attenuator is to: (A) increase signal strength. (B) provide impedance matching. (C) decrease reflections. (D) decrease value of signal strength. Ans: D The purpose of an Attenuator is to decrease value of signal strength. Q.7 In a transmission line terminated by characteristic impedance, ZO
(A) There is no reflection of the incident wave. (B) The reflection is maximum due to termination. (C) There are a large number of maximum and minimum on the line. (D) The incident current is zero for any applied signal. Ans: A
In a transmission line terminated by characteristic impedance, Zo there is no reflection of the incident wave. Q.8 For a coil with inductance L and resistance R in series with a capacitor C has (A) Resonance impedance as zero. (B) Resonance impedance R. (C) Resonance impedance L/CR. (D) Resonance impedance as infinity. Ans: B
For a coil with inductance L and resistance R in series with a capacitor C has a resonance impedance R. Q.9 Laplace transform of a unit Impulse function is (A)s. (B) 0. (C) e-S (D) 1.
Laplace transform of a unit Impulse function is 1 Q.10 Millman’s theorem is applicable during determination of (A) Load current in a network of generators and impedances with two output terminals. (B) Load conditions for maximum power transfer. (C) Dual of a network. (D) Load current in a network with more than one voltage source. Ans: D Millman’s theorem is applicable during determination of Load current in a network with more than one voltage source. Q.12 An attenuator is a (A) R’s network. (B) RL network. (C) RC network. (D) LC network. Ans: A An attenuator is a R’s network. Q.13 A pure resistance, RL when connected at the load end of a loss-less 100 Ω line produces a VSWR of 2. Then R is (A) 50 Ω only. (B) 200 Ω only. (C) 50 Ω or 200 Ω. (D) 400 Ω. Ans: C
A pure resistance, RL when connected at the load end of a loss-less 100 Ωline produces a VSWR of 2. Then RL is 50 Ω or 200 Ω, as follows: Q.14 All pass filter
(A) passes whole of the audio band.
(B) passes whole of the radio band.
(C) passes all frequencies with very low attenuation.
(D) passes all frequencies without attenuation but phase is changed. Ans: D All pass filters, passes all frequencies without attenuation but phase change. Q.16 A series resonant circuit is inductive at f = 1000 Hz. The circuit will be capacitive some where at
(A) f > 1000 Hz.
(B) f < 1000 Hz.
(C) f equal to 1000 Hz and by adding a resistance in series.
(D) f = 1000+ fO ( resonance frequency)
A series resonant circuit is inductive at f = 1000 Hz. The circuit will be capacitive some where at f < 1000 Hz. Q.17 Compensation theorem is applicable to
(A) non-linear networks. (B) linear networks. (C) linear and non-linear networks. (D) None of the above.
Compensation theorem is applicable to linear and non-linear networks. Q.19 A network function is said to have simple pole or simple zero if
(A) the poles and zeroes are on the real axis.
(B) the poles and zeroes are repetitive.
(C) the poles and zeroes are complex conjugate to each other.
(D) the poles and zeroes are not repeated.
Ans: D A network function is said to have simple pole or simple zero if the poles and zeroes are not repeated. Q.20 A delta connection contains three impedances of 60 Ω each. The impedances of equivalent star connection will be
(A) 15 Ωeach. (B) 20 Ω each. (C) 30 Ω each. (D) 40 Ω each.
(B) equivalent voltage source.
(C) equivalent voltage OR current source.
(D value of current in milli amperes input to a circuit from a voltage source.
Ans: C Millman’s theorem yields equivalent voltage or current source. Q.22 The z-parameters of the shown T-network at Fig.1 are given by (A) 5, 8, 12, 0
(B) 13, 8, 8, 20
(C) 8, 20, 13, 12
(D) 5, 8, 8, 12
Q.23 The “Superposition theorem” is essentially based on the concept of (A) duality. (B) linearity. (C) reciprocity. (D) non-linearity. Ans: B Q.24 The power factor of a purely resistive circuit is (A) zero. (B) unity. (C) lagging. (D) leading. Ans: B Q.25