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MCQOPTIONS
This section includes 1800 Mcqs, each offering curated multiple-choice questions to sharpen your Electronics & Communication Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 1101. |
The condition AD - BC = 1 for two port network implies that the network is a |
| A. | reciprocal |
| B. | lumped element network |
| C. | lossless network |
| D. | unilateral element network |
| Answer» B. lumped element network | |
| 1102. |
A two branch parallel tuned circuit has a coil of resistance 100 Ω and inductance 0.005 H in one branch and 10 nF capacitor in the second branch. At resonance frequency is |
| A. | 100 rad/sec |
| B. | 10000 rad/sec |
| C. | 1000 rad/sec |
| D. | more than 10000 rad/sec |
| Answer» D. more than 10000 rad/sec | |
| 1103. |
Consider the following statement : If a network has an impedance of (1 - j) as a specific frequency, the circuit would consist of series R and CR and LR, L and C Which of the statement are correct? |
| A. | 1 and 2 |
| B. | 1 and 3 |
| C. | 1, 2 and 3 |
| D. | 2 and 3 |
| Answer» C. 1, 2 and 3 | |
| 1104. |
Which of the following polynomials is not Hurwitz? |
| A. | P1 = s8 + 2s6 + 4s4 |
| B. | P2 = s6 - 3s4 + 2s2 + 1 |
| C. | P3 = s4 + 3s3 + 3s2 + 2s + 1 |
| D. | P4 = s7 + 2s6 2s4 + 4s3 + 8s2 + 8s + 4 |
| Answer» C. P3 = s4 + 3s3 + 3s2 + 2s + 1 | |
| 1105. |
In the circuit of figure, the switch is closed at t = 0 with iL (0) = 0 and VC (0) = 0. In the steady state nc equals. |
| A. | 100 v |
| B. | 0 v |
| C. | ‚àû |
| D. | - 100 v |
| Answer» B. 0 v | |
| 1106. |
Thevenin's equivalent circuit |
| A. | can be drawn only in time domain |
| B. | can be drawn only in frequency domain |
| C. | can be drawn both in time and frequency domain |
| D. | can be drawn in frequency domain with some restrictions |
| Answer» D. can be drawn in frequency domain with some restrictions | |
| 1107. |
Current density J, conductivity σ and electric field E in a conductor are related as |
| A. | J = σE |
| B. | σ = JE |
| C. | |
| Answer» B. œÉ = JE | |
| 1108. |
When an alternating current passes through an ohmic resistance the electrical power converted into heat is |
| A. | apparent power |
| B. | true power |
| C. | reactive power |
| D. | none of the above |
| Answer» C. reactive power | |
| 1109. |
When a series RL circuit is switched on to a dc voltage, the rate of change of current is maximum at t = 0. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 1110. |
For the time domain response shown in figure the pole |
| A. | lies on negative real axis |
| B. | lies on positive real axis |
| C. | lies on imaginary axis |
| D. | is complex or imaginary |
| Answer» B. lies on positive real axis | |
| 1111. |
In figure, the switch is closed at t = 0. At t = 0+, di/dt = 4 A/s. Then V = |
| A. | 10 V |
| B. | 20 V |
| C. | 40 V |
| D. | 80 V |
| Answer» E. | |
| 1112. |
The current through a 1 mH inductance is i(t) = 2.56 x 10-2 - 4 x 103 t for 2 ≤ t ≤ 20 μ sec. The voltage across the inductor is |
| A. | 4 |
| B. | 8 |
| C. | 0 |
| D. | 8 x 103 |
| Answer» B. 8 | |
| 1113. |
Which one of the following is a cut set of the graph in the given figure? |
| A. | 1, 2, 3, and 4 |
| B. | 2, 3, 4, and 6 |
| C. | 1, 4, 5, and 6 |
| D. | 1, 3, 4, and 5 |
| Answer» E. | |
| 1114. |
Assertion (A): A band elimination filter attenuates signals whose frequencies lie between the cutoff frequencies.Reason (R): A band elimination circuit is very different from band pass circuit. |
| A. | Both A and R are true and R is correct explanation of A |
| B. | Both A and R are true and R is not the correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» C. A is true but R is false | |
| 1115. |
A coil is wound having a diameter d. Its inductance is 10 mH. If it is rewound on the same core with a wire having diameter 0.5 d and total weight of the wire is the same as before, the inductance will be |
| A. | 5 mH |
| B. | 10 mH |
| C. | 160 mH |
| D. | 40 mH |
| Answer» D. 40 mH | |
| 1116. |
A black box has one of the elements our of R, L, C. when a 220 V a supply is connected the current supplied by source is I. when a 0.1 F capacitor is connected in parallel with the box, the current is 2I. The element is |
| A. | resistance |
| B. | inductance |
| C. | 0.1 F capacitance |
| D. | not identifiable on the basis of given data |
| Answer» C. 0.1 F capacitance | |
| 1117. |
Two capacitors of 1 μF and 2 μF capacitance are connected in parallel across a 30 V dc battery. After the capacitors have been charged, the charges across the two capacitors will be |
| A. | 30 μC each |
| B. | 60 μC each |
| C. | 30 μC and 60 μC respectively |
| D. | 60 μC and 30 μC respectively |
| Answer» D. 60 ŒºC and 30 ŒºC respectively | |
| 1118. |
If resistance is 20 Ω and inductance is 2 H in a R-L series circuit, then time constant of this will be |
| A. | 0.001 s |
| B. | 0.1 s |
| C. | 10 s |
| D. | 100 s |
| Answer» C. 10 s | |
| 1119. |
The circuit in figure, the switched on at t = 0. After a long time the current through 5 Ω resistance is |
| A. | 0.041666666666667 |
| B. | 0.16666666666667 |
| C. | 0.41666666666667 |
| D. | 0 |
| Answer» E. | |
| 1120. |
A series circuit has fixed resistance and variable reactance. The impedance locus will be a straight line parallel to Y-axis. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 1121. |
If the peak value of output of a half wave rectifier is 100 V, the rms value is |
| A. | 100 V |
| B. | 50 V |
| C. | 70.7 V |
| D. | 35.35 V |
| Answer» C. 70.7 V | |
| 1122. |
Laplace transform method enables us to find the response in |
| A. | steady state |
| B. | transient state |
| C. | both steady and transient state |
| D. | transient state provided forcing functions do not exist |
| Answer» D. transient state provided forcing functions do not exist | |
| 1123. |
Two capacitors of 20 μF each are in series. The total capacitance is |
| A. | 5 μF |
| B. | 10 μF |
| C. | 40 μF |
| D. | 400 μF |
| Answer» C. 40 ŒºF | |
| 1124. |
The network shown in figure is |
| A. | reciprocal |
| B. | reciprocal and symmetrical |
| C. | non-reciprocal |
| D. | unsymmetrical |
| Answer» D. unsymmetrical | |
| 1125. |
A sine wave of voltage varies from zero to maximum of 200V. How much is the voltage at the instant of 30° of the cycle? |
| A. | 50 V |
| B. | 82.8 V |
| C. | 100 V |
| D. | 173.2 V |
| Answer» D. 173.2 V | |
| 1126. |
In a series R-L circuit when excited by a 1 volt battery the current is 1 - e-t. If it is excited by a source 2 sin t, the current will be |
| A. | 2 sin (t - 45°) + e-t |
| B. | 2 sin (t + 45°) + e-t |
| C. | sin (t - 45°) + e-t |
| D. | sin (t + 45°) + e-t |
| Answer» B. 2 sin (t + 45¬∞) + e-t | |
| 1127. |
In an RLC series circuit having finite values of RLC, the phase difference between applied voltage and current is |
| A. | always 0° |
| B. | between 0 and 180° |
| C. | between 0 and 90° |
| D. | always 90° |
| Answer» E. | |
| 1128. |
If Fourier transform of f(t) is F(jω), then which pairs of time functions and Fourier transforms are matched f (t + 2) - ej2ω F(jω)f (-0.5t) - 2F (-2jω) - Select the answer using the following codes |
| A. | 1 and 2 |
| B. | 1 and 3 |
| C. | 2 and 3 |
| D. | 1, 2 and 3 |
| Answer» B. 1 and 3 | |
| 1129. |
A constant k low pass filter has fc = 500 Hz. At f = 1000 Hz, the attenuation is |
| A. | zero |
| B. | infinity |
| C. | may be zero or infinity |
| D. | more than zero but less than infinity |
| Answer» E. | |
| 1130. |
For a nonlinear resistance |
| A. | v-i plot is not a straight line |
| B. | resistance increases as current increases |
| C. | resistance decreases as current increases |
| D. | current decreases as voltage increases |
| Answer» B. resistance increases as current increases | |
| 1131. |
When a circuit is excited by ac sinusoidal source, the admittance is obtained by letting s = jω in Y(s). |
| A. | 1 |
| B. | |
| Answer» B. | |
| 1132. |
Which of the following is true for RC impedance? |
| A. | The lowest critical frequency is a pole |
| B. | The lowest critical frequency is zero |
| C. | The lowest critical frequency may be pole or zero |
| D. | The lowest critical frequency is a pole but cannot be at s = 0 |
| Answer» B. The lowest critical frequency is zero | |
| 1133. |
Cells are connected in series to increase |
| A. | current-rating |
| B. | both voltage and current rating |
| C. | the life of cell |
| D. | voltage rating |
| Answer» E. | |
| 1134. |
Assertion (A): Peak to peak value of a sinusoidal wave is 2.828 times the rms value.Reason (R): Peak factor of a sinusoidal wave is 1.414. |
| A. | Both A and R are true and R is correct explanation of A |
| B. | Both A and R are true and R is not the correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» B. Both A and R are true and R is not the correct explanation of A | |
| 1135. |
If two networks are connected in parallel then equivalent y parameter of both is |
| A. | [y] = [ya] [yb] |
| B. | [y] = [ya] + [yb] |
| C. | [y] = [ya]/[yb] |
| D. | none |
| Answer» C. [y] = [ya]/[yb] | |
| 1136. |
For a sine wave the average value is calculated over half the cycle. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 1137. |
In a purely inductive circuit, the current __________ the voltage by __________ . |
| A. | lags, 0° |
| B. | leads, 90° |
| C. | lags, 90° |
| D. | lags, 45° |
| Answer» E. | |
| 1138. |
A battery charger can drive a current of 5A with 1Ω resistance connected at its output. If it can charge 2 V battery at 7 A rate, its Thevenin's equivalent circuit will be |
| A. | 7.5 in series with 0.5 Ω resistance |
| B. | 1.25 V in series with 1.5 Ω resistance |
| C. | 7.5 V in parallel with 0.5 Ω resistance |
| D. | 12.5 V in parallel with 1.5 Ω resistance |
| Answer» B. 1.25 V in series with 1.5 Œ© resistance | |
| 1139. |
Which of the statement is correct? |
| A. | h and g matrices are inverse of each other |
| B. | z and y matrices are inverse of each other |
| C. | for reciprocal networks AD - BC = 1 |
| D. | ABCD parameters are used in transistor circuit |
| Answer» E. | |
| 1140. |
One ampere means the flow of |
| A. | One coulomb each minute |
| B. | One electron per second |
| C. | One coulomb per second |
| D. | One coulomb each hour |
| Answer» D. One coulomb each hour | |
| 1141. |
At t = 0+, the current i1 is |
| A. | - V/2R |
| B. | - V/4R |
| C. | - V/R |
| D. | zero |
| Answer» D. zero | |
| 1142. |
When a constant voltage source and constant current source are in series, the current source is ineffective. |
| A. | 1 |
| B. | |
| Answer» C. | |
| 1143. |
The realization of a reactance function gives |
| A. | a network having inductances only |
| B. | a network having capacitances only |
| C. | a network having resistances only |
| D. | a network having inductances and capacitances only |
| Answer» D. a network having inductances and capacitances only | |
| 1144. |
A two branch parallel circuit has a 10 Ω resistance and 0.5 H inductance in one branch and a 100 μF capacitor in the second branch. It is fed from 100 V ac supply. At resonance, the source current is |
| A. | 0.41666666666667 |
| B. | 0.041666666666667 |
| C. | 0.2 A |
| D. | 0.05 A |
| Answer» D. 0.05 A | |
| 1145. |
Assertion (A): The inductance of an iron cored solenoid is not constant.Reason (R): BH curve of an iron specimen is non-linear. |
| A. | Both A and R are true and R is correct explanation of A |
| B. | Both A and R are true and R is not the correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» B. Both A and R are true and R is not the correct explanation of A | |
| 1146. |
In a network |
| A. | Number of links = Number of branches - number of nodes + 1 |
| B. | Number of links = Number of branches - number of nodes |
| C. | Number of links = Number of branches - number of nodes - 1 |
| D. | Number of links = Number of branches - number of nodes - 2 |
| Answer» B. Number of links = Number of branches - number of nodes | |
| 1147. |
Vth = 0, if |
| A. | there is no independent source in circuit |
| B. | there is no dependent source in circuit |
| C. | voltage source of infinite magnitude |
| D. | none |
| Answer» B. there is no dependent source in circuit | |
| 1148. |
In an electrochemical process the mass of material deposited at an electrode is proportional to |
| A. | time for which current is passed |
| B. | magnitude of current |
| C. | electric charge through the electrolyte |
| D. | none of the above |
| Answer» D. none of the above | |
| 1149. |
The impedance parameter z21 is |
| A. | transfer impedance at port 1 with port 2 open circuited |
| B. | transfer impedance at port 1 with port 2 short circuited |
| C. | transfer impedance at port 2 with port 1 open circuited |
| D. | transfer impedance at port 2 with port 1 short circuited |
| Answer» B. transfer impedance at port 1 with port 2 short circuited | |
| 1150. |
A short-circuit is that which is |
| A. | used short pieces of wire |
| B. | goes only a short distance |
| C. | is used for dimming light |
| D. | offer very low resistance path for current to flow |
| Answer» E. | |