MCQOPTIONS
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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.
| 1151. |
In a series R-L-C circuit, the voltage across inductance will be maximum |
| A. | at resonance frequency |
| B. | just before resonant frequency |
| C. | just after resonant frequency |
| D. | none of the above |
| Answer» D. none of the above | |
| 1152. |
In admittance parameter set, the dependent variables are the currents at the two ports. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 1153. |
The zeros of a minimum phase function lie on |
| A. | imaginary axis |
| B. | left half plane or origin |
| C. | left half plane or imaginary axis |
| D. | right half plane or origin |
| Answer» D. right half plane or origin | |
| 1154. |
In an ac circuit that delivers constant power at varying p.f., the current is |
| A. | lowest when p.f. is leading |
| B. | lowest when p.f. is lagging |
| C. | lowest when p.f is unity |
| D. | the same for all power factors |
| Answer» D. the same for all power factors | |
| 1155. |
Colour code of carbon resistors has only two bands. |
| A. | 1 |
| B. | |
| Answer» C. | |
| 1156. |
A capacitor used for power factor correction in single- phase circuit decreases |
| A. | the power factor |
| B. | the line current |
| C. | both the line current and the power factor |
| D. | the line current and increases power factor |
| Answer» E. | |
| 1157. |
An ac circuit has two branches in parallel. The impedances of the two branches are equal. The p.f. of one branch is 0.8 lagging and 0.8 leading. The overall p.f. is |
| A. | zero |
| B. | 0.5 lagging |
| C. | 1 |
| D. | 0.7 lagging |
| Answer» E. | |
| 1158. |
Assertion (A): Thevenin's theorem helps us to find current in a branch of a network for different values of impedances of that branch.Reason (R): Thevenin's equivalent circuit replaces a network by a voltage source in series with impedance. |
| 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 | |
| 1159. |
If admittance of a circuit is defined as , then at resonance |
| A. | mp = ql |
| B. | mq = pl |
| C. | ml = pq |
| D. | none |
| Answer» B. mq = pl | |
| 1160. |
A network is said to be non-linear if it does not satisfy |
| A. | homogeneity condition |
| B. | superposition condition |
| C. | both (a) and (b) |
| D. | associative condition |
| Answer» D. associative condition | |
| 1161. |
For maximum transfer of power, internal resistance of the source should be |
| A. | equal to load resistance |
| B. | less than the load resistance |
| C. | greater than the load resistance |
| D. | none of the above |
| Answer» B. less than the load resistance | |
| 1162. |
All network theorems of dc are applicable to ac also with different quantities taken as phasors. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 1163. |
If a driving point function N(s) = p(s)/q(s), then |
| A. | the degree of p(s) and q(s) may differ by one only |
| B. | the degree of p(s) and q(s) may differ by zero only |
| C. | the degrees of p(s) and q(s) be equal |
| D. | the degrees of p(s) and q(s) must not be equal |
| Answer» C. the degrees of p(s) and q(s) be equal | |
| 1164. |
Nichrome is used in |
| A. | heater coils |
| B. | underground cables |
| C. | overheated wires |
| D. | lamp filament |
| Answer» B. underground cables | |
| 1165. |
In the figure shown, assume that all the capacitors are initially unchanged and Vi(t) = 10 U(t) volts then V0(t) is given by |
| A. | 8 e-0.004t volts |
| B. | 8 (j - e-0.004t) volts |
| C. | 8 u(t) volts |
| D. | 8 volts |
| Answer» C. 8 u(t) volts | |
| 1166. |
An RL series circuit has an impedance of 20 Ω when frequency is 25 Hz. At f= 50 Hz, the impedance will be |
| A. | 40 Ω |
| B. | 20 Ω |
| C. | less than 40 W but more than 20 Ω |
| D. | less than 20 W but more than 10 Ω |
| Answer» D. less than 20 W but more than 10 Œ© | |
| 1167. |
Which of the following theorems is a manifestation of law of conservation of energy? |
| A. | Tellegen's theorem |
| B. | Reciprocity theorem |
| C. | Thevenin's theorem |
| D. | Norton's theorem |
| Answer» B. Reciprocity theorem | |
| 1168. |
If A = 3 + j1 and B = 4 + j3, A + B = |
| A. | 7 ∠45° |
| B. | 10 ∠45° |
| C. | 8.062 ∠29.7° |
| D. | 8.062 ∠73° |
| Answer» D. 8.062 ‚à†73¬∞ | |
| 1169. |
A periodic voltage has following values for equal time intervals changing suddenly from one value to next, 0, 5, 10, 20, 50, 60, 50, 20, 10, 5, 0, -5, -10 etc. then rms value of the waveform is |
| A. | 31 volt |
| B. | 32 volt |
| C. | insufficient data |
| D. | none |
| Answer» B. 32 volt | |
| 1170. |
A zinc carbon cell is a primary cell. |
| A. | 1 |
| B. | |
| Answer» C. | |
| 1171. |
A copper coil has a resistance of 40 ohm at 20°C. At 100°C the resistance is likely to be |
| A. | 44 Ω |
| B. | 54 Ω |
| C. | 84 Ω |
| D. | 104 Ω |
| Answer» C. 84 Œ© | |
| 1172. |
In a 3 phase system, the zero sequence component of line to line voltages is zero |
| A. | if line to line voltages are balanced |
| B. | if line to line voltages are unbalanced |
| C. | if line to line voltages are balanced or unbalanced |
| D. | if degree of unbalanced in line to line voltages is small |
| Answer» D. if degree of unbalanced in line to line voltages is small | |
| 1173. |
Volume control found on the front panel of television receivers |
| A. | a ganged resistor |
| B. | a variable resistor of logarithmic type |
| C. | a variable resistor of linear type |
| D. | a trimmer potentiometer |
| Answer» C. a variable resistor of linear type | |
| 1174. |
The voltage e0 in the figure |
| A. | 48 V |
| B. | 24 V |
| C. | 36 V |
| D. | 28 V |
| Answer» E. | |
| 1175. |
A series circuit having R = 3 Ω and L = 2 H is excited by a 10 V battery. At t = 0+, di/dt is |
| A. | 5 A/s |
| B. | |
| C. | 20 A/s |
| Answer» B. | |
| 1176. |
In a series RC circuit Z = (R2 + ω2C2)0.5. |
| A. | 1 |
| B. | |
| Answer» C. | |
| 1177. |
For the following circuit a source of V1(t) = e-2t is applied, then the resulting response V2(t) is given by |
| A. | e-2t + e-t |
| B. | e-t |
| C. | e-t - e-2t |
| Answer» D. | |
| 1178. |
An RC circuit initially at rest has a step signal. The response V(t) across C is V(t) = 1 - e-at, If now there is an initial voltage on C of 2 volts for the same step signal, V(t) is now |
| A. | 1 + e -at |
| B. | 1 + 2e -at |
| C. | 2 - e -at |
| D. | 3 - e -at |
| Answer» B. 1 + 2e -at | |
| 1179. |
In the circuit of figure, the source supplies, 2.25 mA. The value of R must be |
| A. | 5 Ω |
| B. | 3 Ω |
| C. | 1.5 Ω |
| D. | 0.5 Ω |
| Answer» C. 1.5 Œ© | |
| 1180. |
In a series RLC circuit, R = 2 kΩ, L = 1H and The resonant frequency is |
| A. | 2 x 104 Hz |
| B. | 1/p x 104 Hz |
| C. | 104 Hz |
| D. | 2p x 104 Hz |
| Answer» C. 104 Hz | |
| 1181. |
An RLC series circuit is excited by a step voltage E. The units of roots of characteristic equation are |
| A. | seconds |
| B. | 1/seconds |
| C. | tesla |
| D. | henry |
| Answer» C. tesla | |
| 1182. |
An RLC series circuit has R = 1 Ω, L = 1 H, C = 1 F. The damping ratio is |
| A. | More than 1 |
| B. | 1 |
| C. | 0.5 |
| D. | Zero |
| Answer» D. Zero | |
| 1183. |
Dielectric materials have high specific resistance. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 1184. |
In figure, i(0-) and v(0-) are zero. The switch is closed at t = 0, i(0+) and (‚àû) are |
| A. | 3 A and 1.5 A |
| B. | 1.5 A and zero |
| C. | 3 A and zero |
| D. | 1.5 A and 3 A |
| Answer» D. 1.5 A and 3 A | |
| 1185. |
A system is said to be marginal stable if |
| A. | poles lies on Real axis |
| B. | zero lies on Real axis |
| C. | poles lies on Imaginary axis |
| D. | zeros lies on origin |
| Answer» D. zeros lies on origin | |
| 1186. |
In an idealized half wave rectified system the average and r.m.s. values of voltage are __________ respectively. |
| A. | 2Vm/p, Vm/2 |
| B. | Vm/p, Vm/2 |
| C. | Vm/p, Vm/2 |
| D. | Vm.p, Vm/2 |
| Answer» C. Vm/p, Vm/2 | |
| 1187. |
In figure, the short circuit current through terminal AB will be |
| A. | 0.125 |
| B. | 1.5 A |
| C. | 0.083333333333333 |
| D. | 0.041666666666667 |
| Answer» B. 1.5 A | |
| 1188. |
For a delayed half wave rectified wave, the average and rms values are lower than those for half wave. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 1189. |
In following circuit, steady state is reached with S open, S is closed at t = 0, the current I at t = 0+ is given by |
| A. | 9 Ω |
| B. | 6 Ω |
| C. | 7 Ω |
| D. | 10 Ω |
| Answer» D. 10 Œ© | |
| 1190. |
A resistor is rated at 0.75 watt, 1 kΩ. Its current rating is |
| A. | 1 mA |
| B. | 27.386 mA |
| C. | 1.268 mA |
| D. | 5.393 mA |
| Answer» C. 1.268 mA | |
| 1191. |
In figure, the switch has been closed position for a long time. At t = 0 the switch is opened. At t = 0+, the current ic is |
| A. | I |
| B. | 0 |
| C. | infinite |
| Answer» B. 0 | |
| 1192. |
Discharge breakdown in insulators is due to voids. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 1193. |
In ZRC (s) has a pole at s = ‚àû, the last element in first Foster realization is |
| A. | R |
| B. | C |
| C. | R and C in series |
| D. | R and C in parallel |
| Answer» B. C | |
| 1194. |
In a 5.6 ohms, ± 10% carbon composition resistor, the colour of the third strip from extreme left is |
| A. | golden |
| B. | silver |
| C. | green |
| D. | black |
| Answer» B. silver | |
| 1195. |
In steady state condition inductor behave as |
| A. | open circuit |
| B. | short circuit |
| C. | current source |
| D. | voltage source |
| Answer» C. current source | |
| 1196. |
The series element for a prototype high pass filter is |
| A. | resistive |
| B. | inductive |
| C. | capacitive |
| D. | combination of L and C |
| Answer» D. combination of L and C | |
| 1197. |
When tracing through a resistance we always get a voltage drop. |
| A. | 1 |
| B. | |
| Answer» C. | |
| 1198. |
In a series resonant circuit Q is more than 10. Then the lower half power frequency ω1, and resonant frequency ω0 are related as |
| A. | ω1 = ω0 + bandwidth |
| B. | ω1 = ω0 + 0.5 (bandwidth) |
| C. | ω1 = ω0 - 0.5 (bandwidth) |
| D. | ω1 = ω0 + bandwidth |
| Answer» D. œâ1 = œâ0 + bandwidth | |
| 1199. |
If figure, power dissipated in 30Ω resistance will be maximum when value of R = |
| A. | 30 Ω |
| B. | 16 Ω |
| C. | 9 Ω |
| D. | zero |
| Answer» D. zero | |
| 1200. |
The factor which will have least effect on the voltage at the load end of a two-wire supply circuit is |
| A. | length of the circuit |
| B. | whether supply frequency is 25 Hz or 50 Hz |
| C. | amount of load on the circuit |
| D. | cross-section of the circuit wires |
| Answer» C. amount of load on the circuit | |