MCQOPTIONS
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MCQOPTIONS
This section includes 147 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 101. |
The arc resistance depends on which among the following factors? |
| A. | Cross section of the arc. |
| B. | Length of the arc |
| C. | Degree of ionization |
| D. | All of the above. |
| Answer» E. | |
| 102. |
Which type of tripping is generally preferred for the circuit breaker? |
| A. | Manual |
| B. | Automatically |
| C. | Depending on the voltage level |
| D. | None of the above |
| Answer» C. Depending on the voltage level | |
| 103. |
Which part of the circuit breaker is helpful in breaking the current? |
| A. | Trip coil |
| B. | Contacts |
| C. | Medium |
| D. | Handle. |
| Answer» C. Medium | |
| 104. |
When a fault occurs in a high voltage transmission line, what happens first? |
| A. | Circuit breaker operates then the relay. |
| B. | Relay operates and then the circuit breaker. |
| C. | Relay operates, then successively the isolator and the circuit breaker. |
| D. | Isolator operates, then successively the relay and the circuit breaker. |
| Answer» C. Relay operates, then successively the isolator and the circuit breaker. | |
| 105. |
Upto what voltage can the liquid type HRC fuses be used? |
| A. | 33 kV |
| B. | 132 kV |
| C. | 66 kV |
| D. | 220 kV |
| Answer» C. 66 kV | |
| 106. |
What is the main advantage of using a fuse? |
| A. | Cheapest type of protection. |
| B. | Inverse time current characteristics. |
| C. | Current limiting effect under short circuit conditions |
| D. | All of above. |
| Answer» E. | |
| 107. |
On what basis is the selection of fuse done? |
| A. | Steady load. |
| B. | Fluctuating load. |
| C. | Both (a) and (b) |
| D. | None of these |
| Answer» D. None of these | |
| 108. |
Upto what voltage a cartridge type of fuse can be used? |
| A. | 400 V |
| B. | . 11 kV |
| C. | 20 kV |
| D. | 33 kV |
| Answer» E. | |
| 109. |
In a HRC fuse what is the time between the cut off and the final current zero called? |
| A. | Pre – arcing time. |
| B. | Arcing time. |
| C. | Total operating time |
| D. | None of these. |
| Answer» C. Total operating time | |
| 110. |
Which material is used in the liquid type of fuse? |
| A. | SF6 |
| B. | Distilled water |
| C. | Carbon tetra chloride. |
| D. | Mineral oil / transformer oil |
| Answer» D. Mineral oil / transformer oil | |
| 111. |
What is the advantage of HRC fuses over Rewirable fuses? |
| A. | High speed operation |
| B. | High rupturing capacity |
| C. | No ageing effect. |
| D. | All of the above |
| Answer» E. | |
| 112. |
What is the cut off current in the fuse? |
| A. | Maximum value actually reached. |
| B. | Rms value actually reached. |
| C. | Average value actually reached. |
| D. | None of the above |
| Answer» B. Rms value actually reached. | |
| 113. |
If the strands of the fusing wire are twisted, what happens to the fusing current? |
| A. | Increases |
| B. | Reduces |
| C. | No change/ remains same |
| D. | Depends on the value of current, increases or decreases. |
| Answer» C. No change/ remains same | |
| 114. |
Which among these tests are performed to check the nation or international standards? |
| A. | Type test. |
| B. | Production tests. |
| C. | Site checks. |
| D. | All of the above. |
| Answer» B. Production tests. | |
| 115. |
A fuse wire of circular cross section has a radius of 0.8mm. The wire blows off at a current of 9A. What will be the radius of the wire that will blow off at a current of 1A? |
| A. | 0.2 mm |
| B. | 0.18 mm |
| C. | 0.28 mm |
| D. | 0.3 mm |
| Answer» C. 0.28 mm | |
| 116. |
What is the typical value of the pre arcing time? |
| A. | 0.1 |
| B. | 0.01 |
| C. | 0.001 |
| D. | 0.0001 |
| Answer» E. | |
| 117. |
What is the maximum current upto which fuses can be used? |
| A. | 25 A |
| B. | 50 A |
| C. | 75 A |
| D. | 100 A |
| Answer» B. 50 A | |
| 118. |
What should be the value of fusing factor? |
| A. | Equal to zero |
| B. | Equal to one |
| C. | Less than one |
| D. | More than one |
| Answer» D. More than one | |
| 119. |
What is the relation between the fusing current and the diameter of the wire? |
| A. | I = k d3 |
| B. | I = k d3/2 |
| C. | I = k d2 |
| D. | I = k d2/3 |
| Answer» C. I = k d2 | |
| 120. |
For a current upto 10A which material is used as the fusing element? |
| A. | Copper |
| B. | Silver |
| C. | Alloy of lead and tin |
| D. | Zinc |
| Answer» D. Zinc | |
| 121. |
Which among these is the least expensive protection for over current in low voltage system? |
| A. | Rewirable fuse |
| B. | Isolator. |
| C. | Circuit breaker. |
| D. | Air breaker switch. |
| Answer» B. Isolator. | |
| 122. |
Which among the following statement is true related to fuse? |
| A. | Greater the current smaller is the time taken by the fuse to blow out. |
| B. | Greater the current greater is the time taken by the fuse to blow out. |
| C. | The current is directly proportion to the blow out time of fuse. |
| D. | Is dependent on the temperature and atmospheric conditions |
| Answer» B. Greater the current greater is the time taken by the fuse to blow out. | |
| 123. |
Which among these are the main characteristics of a fuse element? |
| A. | Low melting point |
| B. | High conductivity |
| C. | Least deterioration due to oxidation |
| D. | All of the above |
| Answer» E. | |
| 124. |
How is the bus bars rated? |
| A. | Current only |
| B. | Voltage only. |
| C. | Current, voltage and frequency. |
| D. | Current, voltage, frequency and short circuit current. |
| Answer» E. | |
| 125. |
Which material is used for the manufacture of bus bars? |
| A. | Aluminium rods. |
| B. | Copper rods. |
| C. | Any conducting material. |
| D. | Made of silver. |
| Answer» C. Any conducting material. | |
| 126. |
Which device sends the information to the circuit breaker to interrupt the circuit in case of fault? |
| A. | Switch |
| B. | Relay |
| C. | Circuit breaker itself does this function. |
| D. | Fuse. |
| Answer» C. Circuit breaker itself does this function. | |
| 127. |
When does the circuit breaker operate in the line? |
| A. | When power is to be supplied. |
| B. | When the line is to be tested. |
| C. | Whenever the fault occurs in the line. |
| D. | Whenever the switch and the relay has to be operated. |
| Answer» D. Whenever the switch and the relay has to be operated. | |
| 128. |
What is the primary principle of a fuse? |
| A. | Open the circuit. |
| B. | Protect the appliance. |
| C. | Protect the line |
| D. | Prevent excess current from flowing into the line. |
| Answer» E. | |
| 129. |
What is switchgear? |
| A. | An apparatus used for switching, controlling and protecting the electrical circuits and equipments. |
| B. | It detects the faults only. |
| C. | It corrects the faults only. |
| D. | All of the above |
| Answer» E. | |
| 130. |
KCL is applicable at |
| A. | A Junction |
| B. | Resistor |
| C. | Loop |
| D. | All of these |
| Answer» B. Resistor | |
| 131. |
Circuit is defined as |
| A. | Interconnection OfCircuit Elements With Closed Path |
| B. | Interconnection OfCircuit Elements With Out Any Closed Path |
| C. | Interconnection Of With Out Circuit Elements |
| D. | None of these |
| Answer» B. Interconnection OfCircuit Elements With Out Any Closed Path | |
| 132. |
Two resistors each of 4 and 12 are connected in parallel and the parallel combination is connected in series with a 2 resistor. What is the Equivalent Resistance? |
| A. | 50 |
| B. | 5 |
| C. | 20 |
| D. | 2 |
| Answer» C. 20 | |
| 133. |
Four resistors each of 20 are connected in parallel, the total resistance is |
| A. | 80 |
| B. | 5 |
| C. | 5 |
| D. | None Of These |
| Answer» D. None Of These | |
| 134. |
Two resistances R1 and R2 give combined resistance of 4.5 ohms when in series and 1 ohm when in parallel. The resistances are |
| A. | ohms and 6 ohms |
| B. | 3 ohms and 9 ohms |
| C. | 1.5 ohms and 3 ohms |
| D. | 1.5 ohms and 0.5 ohms |
| Answer» D. 1.5 ohms and 0.5 ohms | |
| 135. |
The polarity of the induced voltage is determined by |
| A. | Ampere’s law |
| B. | Lenz’s law |
| C. | Kirchhoff’s law |
| D. | Right hand rule |
| Answer» C. Kirchhoff’s law | |
| 136. |
Unit of electric potential |
| A. | Ampere |
| B. | Volts |
| C. | coulomb |
| D. | Volt-ampere |
| Answer» C. coulomb | |
| 137. |
An ideal voltage source should have: |
| A. | Zero source resistance |
| B. | Infinite source resistance |
| C. | Terminal voltage is proportional to current |
| D. | Open-circuit voltage nearly equal to voltage of the load current |
| Answer» B. Infinite source resistance | |
| 138. |
The superposition theorem requires as many circuits to be solved as there are: |
| A. | Nodes |
| B. | Sources |
| C. | Nodes and Sources |
| D. | Nodes, Sources and Mesh |
| Answer» C. Nodes and Sources | |
| 139. |
When maximum power transfer takes place, the efficiency of power transfer of the circuit is |
| A. | 100% |
| B. | 75% |
| C. | 50% |
| D. | 25% |
| Answer» D. 25% | |
| 140. |
Which of the following theorems helps in simplifying computations when the load across a circuit is varying? |
| A. | Superposition |
| B. | Norton’s |
| C. | Thevenin’s |
| D. | Maximum power transfer |
| Answer» E. | |
| 141. |
Thevenin’s theorem can be applied to network containing |
| A. | Passive elements only |
| B. | Active elements only |
| C. | Linear elements only |
| D. | All of these |
| Answer» E. | |
| 142. |
For maximum transfer of power, internal resistance of the source should be: |
| A. | Equal to load resistance |
| B. | Less than that of the load |
| C. | More than that of the load |
| D. | Zero |
| Answer» B. Less than that of the load | |
| 143. |
The rating of fuse wire is expressed in terms of |
| A. | Ohms |
| B. | Mhos |
| C. | Amperes |
| D. | Watts. |
| Answer» D. Watts. | |
| 144. |
Ohm’s law is not applicable to |
| A. | DC circuits |
| B. | high currents |
| C. | small resistors |
| D. | semi-conductors. |
| Answer» E. | |
| 145. |
Which of the following is not the same as watt? |
| A. | joule/sec |
| B. | amperes/volt |
| C. | amperes x volts |
| D. | ( amperes )2 x ohm. |
| Answer» C. amperes x volts | |
| 146. |
Resistivity of a wire depends on |
| A. | length |
| B. | material |
| C. | cross section area |
| D. | All of the above. |
| Answer» C. cross section area | |
| 147. |
What will be the resistance if 10 resistors of 10 ohm each is connected in series |
| A. | 100 |
| B. | 1 |
| C. | 0.1 |
| D. | 10 |
| Answer» B. 1 | |