MCQOPTIONS
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MCQOPTIONS
This section includes 234 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 151. |
In order that current should flow without causing excessive heating or voltage drop, the relay contacts should |
| A. | have low contact resistance |
| B. | be clean and smooth |
| C. | be of sufficient size and proper shape |
| D. | have all above properties |
| Answer» E. | |
| 152. |
The relay operating speed depends upon |
| A. | the spring tension |
| B. | the rate of flux built up |
| C. | armature core air gap |
| D. | all of the above |
| Answer» E. | |
| 153. |
D.C. shunt relays are made of |
| A. | few turns of thin wire |
| B. | few turns of thick wire |
| C. | many turns of thin wire |
| D. | many turns of thick wire |
| Answer» D. many turns of thick wire | |
| 154. |
Magnetic circuit breaker has ______ trip action. |
| A. | delayed |
| B. | instantaneous |
| C. | both of the above |
| D. | none of the above |
| Answer» C. both of the above | |
| 155. |
Thermal overload relays are used to protect the motor against over current due to |
| A. | short-circuits |
| B. | heavy loads |
| C. | grounds |
| D. | all of the above |
| Answer» C. grounds | |
| 156. |
Overload relays are of…… type |
| A. | induction |
| B. | solid state |
| C. | thermal |
| D. | all above |
| Answer» E. | |
| 157. |
Relays can be designed to respond to changes in |
| A. | resistance, reactance or impedance |
| B. | voltage and current |
| C. | light intensity |
| D. | all above |
| Answer» E. | |
| 158. |
Thermal circuit breaker has |
| A. | delayed trip action |
| B. | instantaneous trip action |
| C. | both of the above |
| D. | none of the above |
| Answer» B. instantaneous trip action | |
| 159. |
Arc in a circuit behaves as |
| A. | a capackive reactance |
| B. | an inductive reactance |
| C. | a resistance increasing with voltage rise across the arc |
| D. | a resistance decreasing with voltage rise across the arc |
| Answer» E. | |
| 160. |
A thermal protection switch can protect against |
| A. | short-circuit |
| B. | temperature |
| C. | overload |
| D. | over voltage |
| Answer» D. over voltage | |
| 161. |
Fault diverters are basically |
| A. | fuses |
| B. | relays |
| C. | fast switches |
| D. | circuit breakers |
| Answer» D. circuit breakers | |
| 162. |
With which of the following, a circuit breaker must be equipped for remote operation ? |
| A. | Inverse time trip |
| B. | Time-delay trip |
| C. | Shunt trip |
| D. | None of the above |
| Answer» D. None of the above | |
| 163. |
Which of the following medium is employed for extinction of arc in air circuit breaker |
| A. | Water |
| B. | Oil |
| C. | Air |
| D. | SF6 |
| Answer» D. SF6 | |
| 164. |
The arcing contacts in a circuit breaker are made of |
| A. | copper tungsten alloy |
| B. | porcelain |
| C. | electrolytic copper |
| D. | aluminium alloy |
| Answer» B. porcelain | |
| 165. |
SF6 gas |
| A. | is yellow in colour |
| B. | is lighter than air |
| C. | is nontoxic |
| D. | has pungent small |
| Answer» D. has pungent small | |
| 166. |
On which of the following routine tests are conducted ? |
| A. | Oil circuit breakers |
| B. | Air blast circuit breakers |
| C. | Minimum oil circuit breakers |
| D. | All of the above |
| Answer» E. | |
| 167. |
The main function of a fuse is to |
| A. | protect the line |
| B. | open the circuit |
| C. | protect the appliance |
| D. | prevent excessive currents |
| Answer» E. | |
| 168. |
The circuit has resistors, capacitors and semi-conductor diodes. The circuit will be known as |
| A. | non-linear circuit |
| B. | linear circuit |
| C. | bilateral circuit |
| D. | none of the above |
| Answer» B. linear circuit | |
| 169. |
The circuit whose properties are same in either direction is known as |
| A. | unilateral circuit |
| B. | bilateral circuit |
| C. | irreversible circuit |
| D. | reversible circuit |
| Answer» C. irreversible circuit | |
| 170. |
If the energy is supplied from a source, whose resistance is 1 ohm, to a load of 100 ohms the source will be |
| A. | a voltage source |
| B. | a current source |
| C. | both of above |
| D. | none of the above |
| Answer» B. a current source | |
| 171. |
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 | |
| 172. |
If resistance across LM in Fig. 2.30 is 15 ohms, the value of R is |
| A. | 10 Q |
| B. | 20 Q |
| C. | 30 Q |
| D. | 40 Q |
| Answer» D. 40 Q | |
| 173. |
Efficiency of power transfer when maximum transfer of power c xerosis |
| A. | 100% |
| B. | 80% |
| C. | 75% |
| D. | 50% |
| Answer» E. | |
| 174. |
For high efficiency of transfer of power, internal resistance of the source should be |
| A. | equal to the load resistance |
| B. | less than the load resistance |
| C. | more than the load resistance |
| D. | none of the above |
| Answer» C. more than the load resistance | |
| 175. |
The resistance LM will be |
| A. | 6.66 Q |
| B. | 12 Q |
| C. | 18Q |
| D. | 20Q |
| Answer» B. 12 Q | |
| 176. |
Kirchhoff s voltage law applies to circuits with |
| A. | nonlinear elements only |
| B. | linear elements only |
| C. | linear, non-linear, active and passive elements |
| D. | linear, non-linear, active, passive, time varying as wells as time-in-variant elements |
| Answer» E. | |
| 177. |
Kirchhoff s law is not applicable to circuits with |
| A. | lumped parameters |
| B. | passive elements |
| C. | distributed parameters |
| D. | non-linear resistances |
| Answer» D. non-linear resistances | |
| 178. |
A capacitor is generally a |
| A. | bilateral and active component |
| B. | active, passive, linear and nonlinear component |
| C. | linear and bilateral component |
| D. | non-linear and active component |
| Answer» D. non-linear and active component | |
| 179. |
Which of the following is non-linear circuit parameter ? |
| A. | Inductance |
| B. | Condenser |
| C. | Wire wound resistor |
| D. | Transistor |
| Answer» B. Condenser | |
| 180. |
“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 |
| A. | compensation theorem |
| B. | superposition theorem |
| C. | reciprocity theorem |
| D. | none of the above |
| Answer» D. none of the above | |
| 181. |
"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 |
| A. | Millman’s theorem |
| B. | Thevenin’s theorem |
| C. | Superposition theorem |
| D. | Maximum power transfer theorem |
| Answer» E. | |
| 182. |
To determine the polarity of the voltage drop across a resistor, it is necessary to know |
| A. | value of current through the resistor |
| B. | direction of current through the resistor |
| C. | value of resistor |
| D. | e.m.fs. in the circuit |
| Answer» C. value of resistor | |
| 183. |
For a voltage source |
| A. | terminal voltage is always lower than source e.m.f. |
| B. | terminal voltage cannot be higher than source e.m.f. |
| Answer» C. | |
| 184. |
An ideal voltage source should have |
| A. | large value of e.m.f. |
| B. | small value of e.m.f. |
| C. | zero source resistance |
| D. | infinite source resistance |
| Answer» D. infinite source resistance | |
| 185. |
Thevenin resistance Rth is found |
| A. | by removing voltage sources along with their internal resistances |
| B. | by short-circuiting the given two terminals |
| C. | between any two ‘open’ terminals |
| D. | between same open terminals as for Etk |
| Answer» E. | |
| 186. |
The concept on which Superposition theorem is based is |
| A. | reciprocity |
| B. | duality |
| C. | non-linearity |
| D. | linearity |
| Answer» E. | |
| 187. |
Superposition theorem can be applied only to circuits having |
| A. | resistive elements |
| B. | passive elements |
| C. | non-linear elements |
| D. | linear bilateral elements |
| Answer» E. | |
| 188. |
Kirchhoffs voltage law is related to |
| A. | junction currents |
| B. | battery e.m.fs. |
| C. | IR drops |
| D. | both (b) and (c) |
| Answer» E. | |
| 189. |
Kirchhoffs current law is applicable to only |
| A. | junction in a network |
| B. | closed loops in a network |
| C. | electric circuits |
| D. | electronic circuits |
| Answer» B. closed loops in a network | |
| 190. |
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 |
| A. | negative |
| B. | positive |
| C. | determined by battery e.m.fs. |
| D. | zero |
| Answer» E. | |
| 191. |
Kirchhoff s current law states that |
| A. | net current flow at the junction is positive |
| B. | Hebraic sum of the currents meeting at the junction is zero |
| C. | no current can leave the junction without some current entering it. |
| D. | total sum of currents meeting at the junction is zero |
| Answer» C. no current can leave the junction without some current entering it. | |
| 192. |
The most widely used rectifier is ………………. |
| A. | half-wave rectifier |
| B. | centre-tap full-wave rectifier |
| C. | bridge full-wave rectifier |
| D. | none of the above |
| Answer» D. none of the above | |
| 193. |
The maximum efficiency of a half-wave rectifier is ………………. |
| A. | 40.6 % |
| B. | 81.2 % |
| C. | 50 % |
| D. | 25 % |
| Answer» B. 81.2 % | |
| 194. |
A half-wave rectifier has an input voltage of 240 V r.m.s. If the step-down transformer has a turns ratio of 8:1, what is the peak load voltage? Ignore diode drop. |
| A. | 27.5 V |
| B. | 86.5 V |
| C. | 30 V |
| D. | 42.5 V |
| Answer» E. | |
| 195. |
The ……………….. filter circuit results in the best voltage regulation |
| A. | choke input |
| B. | capacitor input |
| C. | resistance input |
| D. | none of the above |
| Answer» B. capacitor input | |
| 196. |
A 1,000 V power supply would use ……….. as a filter capacitor |
| A. | paper capacitor |
| B. | air capacitor |
| C. | mica capacitor |
| D. | electrolytic capacitor |
| Answer» B. air capacitor | |
| 197. |
A 10 V power supply would use …………………. as filter capacitor. |
| A. | paper capacitor |
| B. | mica capacitor |
| C. | electrolytic capacitor |
| D. | air capacitor |
| Answer» D. air capacitor | |
| 198. |
If the PIV rating of a diode is exceeded, ……………… |
| A. | the diode conducts poorly |
| B. | the diode is destroyed |
| C. | the diode behaves like a zener diode |
| D. | none of the above |
| Answer» C. the diode behaves like a zener diode | |
| 199. |
For the same secondary voltage, the output voltage from a centre-tap rectifier is ………… than that of bridge rectifier |
| A. | twice |
| B. | thrice |
| C. | four time |
| D. | one-half |
| Answer» E. | |
| 200. |
The PIV rating of each diode in a bridge rectifier is ……………… that of the equivalent centre-tap rectifier |
| A. | one-half |
| B. | the same as |
| C. | twice |
| D. | four times |
| Answer» B. the same as | |