MCQOPTIONS
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MCQOPTIONS
This section includes 210 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering Questions knowledge and support exam preparation. Choose a topic below to get started.
| 101. |
Which alloy is used as electrical resistance alloy? |
| A. | Nickel alloys |
| B. | Nickel chromium alloys |
| C. | Ferro nickel alloys |
| D. | Only a and b |
| E. | All of these |
| Answer» F. | |
| 102. |
Which alarm is generally used in a DC bus? |
| A. | Over voltage alarm |
| B. | Earth fault alarm |
| C. | Under voltage alarm |
| D. | Only (b) & (c) |
| E. | All of these |
| Answer» F. | |
| 103. |
Where is the synchronous motor drive with cycloconverters used? |
| A. | Compressors |
| B. | Ball mills in cement plants |
| C. | Fans |
| D. | All of these |
| Answer» C. Fans | |
| 104. |
What will be the voltage applied in a routine test for 1minute if the rated voltage of the electrical machine is 400 V? |
| A. | 400 V |
| B. | 1000 V |
| C. | 2000 V |
| D. | 3000 V |
| Answer» D. 3000 V | |
| 105. |
What will be the span of a transmission line carrying a voltage of 11 kV? |
| A. | 200 m |
| B. | 100 m |
| C. | 260 m |
| D. | 80 m |
| Answer» C. 260 m | |
| 106. |
What will be the relay current range in amperes for a 3 phase 50 Hz 12.5 Hp 440 V motor? |
| A. | 13 – 20 A |
| B. | 20 – 30 A |
| C. | 30 – 45 A |
| D. | 6 – 13 A |
| Answer» B. 20 – 30 A | |
| 107. |
What will be the re - lubrication period for ordinary grease for a 1000 rpm motor if it runs for 24 hours a day? |
| A. | 10 weeks |
| B. | 5 weeks |
| C. | 2 weeks |
| D. | 1 week |
| Answer» D. 1 week | |
| 108. |
What will be the rating of heater if the machine to be dried is less than 500 kW? |
| A. | 1.5 - 3 % of the machine rating |
| B. | 3.5 % of the machine rating |
| C. | 5 % of the machine rating |
| D. | 5.5 % of the machine rating |
| Answer» C. 5 % of the machine rating | |
| 109. |
What will be the maximum permissible difference in resistance from the measured value to the manufacturer’s value? |
| A. | ± 3 % |
| B. | ± 2 % |
| C. | ± 5 % |
| D. | ± 1 % |
| Answer» C. ± 5 % | |
| 110. |
What value of DAR ratio indicates a poor insulation? |
| A. | Below 2.5 |
| B. | Below 1.25 |
| C. | Above 1.25 |
| D. | Above 2 |
| Answer» C. Above 1.25 | |
| 111. |
What type of insulation is preferred for DC smoothing Reactors? |
| A. | Air |
| B. | Oil |
| C. | Paper |
| D. | Varnish |
| Answer» C. Paper | |
| 112. |
What type of insulated cable is preferred for distribution lines? |
| A. | PVC and XLPE |
| B. | PVC only |
| C. | XLPE only |
| D. | EPR and XLPE |
| Answer» B. PVC only | |
| 113. |
What type of circuits use static rectifiers? |
| A. | Circuits where storage batteries are not essential |
| B. | Circuits where storage batteries are essential |
| C. | Used in all the AC and DC circuits along with batteries |
| D. | Used in AC circuits only |
| Answer» B. Circuits where storage batteries are essential | |
| 114. |
What test is performed to verify that the equipment is ready for energising? |
| A. | Maintenance test |
| B. | Commissioning test |
| C. | Type test |
| D. | Reliability test |
| Answer» C. Type test | |
| 115. |
What test is conducted on the synchronous motor before completely assembling the whole machine? |
| A. | Speed torque curves |
| B. | Bearing insulation |
| C. | Dielectric tests on the armature windings |
| D. | Measurement of DC resistance of armature winding |
| Answer» C. Dielectric tests on the armature windings | |
| 116. |
What should be the voltage applied for polymeric cables during partial discharge test? |
| A. | A 15 minute DC test at a voltage 2Vo |
| B. | A 15 minute DC test at a voltage 8Vo |
| C. | A 15 minute DC test at a voltage 4Vo |
| D. | A 15 minute DC test at a voltage Vo |
| Answer» D. A 15 minute DC test at a voltage Vo | |
| 117. |
What should be the permissible sag in meters between two towers if the voltage to be carried is 66 kV? |
| A. | 2 – 4 m |
| B. | 5 – 7 m |
| C. | 4 – 5 m |
| D. | 1.5 m |
| Answer» B. 5 – 7 m | |
| 118. |
What should be the frequency of the incoming machine while the machine is synchronising to operate in parallel? |
| A. | Approximately 1 / 10 cycle less than the bus frequency |
| B. | Approximately 1 / 10 cycle higher than the bus frequency |
| C. | Approximately 1 / 100 cycle less than the bus frequency |
| D. | Approximately 1 / 100 cycle higher than the bus frequency |
| Answer» C. Approximately 1 / 100 cycle less than the bus frequency | |
| 119. |
What results if the rotor bar of a squirrel cage rotor is broken? |
| A. | Noise |
| B. | Low starting torque |
| C. | Rated speed is not reached even with rated voltage and frequency |
| D. | All of these |
| E. | None of these |
| Answer» E. None of these | |
| 120. |
What protection is preferred for preventing rotor faults? |
| A. | Thermal relay |
| B. | HRC fuses |
| C. | Instantaneous over current relay |
| D. | Differential protection |
| Answer» D. Differential protection | |
| 121. |
What parameter(s) is / are checked using the commissioning tests? |
| A. | Turbine speed |
| B. | Condenser vacuum |
| C. | Turbine governor valve opening |
| D. | Only b and c |
| E. | All of these |
| Answer» F. | |
| 122. |
What is the voltage characteristic of a differential compound DC motor? |
| A. | Rising |
| B. | Drooping |
| C. | Flat |
| D. | Exponential |
| Answer» C. Flat | |
| 123. |
What is the value of the permanently connected capacitor in capacitor start capacitor run induction motor? |
| A. | 40 μ F |
| B. | 5 μ F |
| C. | 300 μ F |
| D. | 1000 μ F |
| Answer» B. 5 μ F | |
| 124. |
What is the value of R and C in RC surge suppressor? |
| A. | R = 1000 Ω C = 0.01 μ F |
| B. | R = 100 Ω C = 0.1 μ F |
| C. | R = 1000 Ω C = 0.1 μ F |
| D. | R = 100 Ω C = 0.01 μ F |
| Answer» C. R = 1000 Ω C = 0.1 μ F | |
| 125. |
What is the value of open circuit voltage in a dry cell? |
| A. | 2.5 V |
| B. | 2.8 V |
| C. | 1.6 V |
| D. | 3.2 V |
| Answer» D. 3.2 V | |
| 126. |
What is the usual voltage range in the slip rings for the induction motor? |
| A. | 50 V to 115 V |
| B. | 100 V to 1 kV |
| C. | Is proportional to the stator voltages |
| D. | None of these |
| Answer» C. Is proportional to the stator voltages | |
| 127. |
What is the usual rating of a synchronous induction motor? |
| A. | Below 25 kW |
| B. | Below 5 kW |
| C. | Above 30 kW |
| D. | Above 100 kW |
| Answer» B. Below 5 kW | |
| 128. |
What is the use of current transformers? |
| A. | Stepping up AC current |
| B. | Measuring and protection |
| C. | Stepping down AC current |
| D. | Both (b) and (c) |
| E. | All of these |
| Answer» E. All of these | |
| 129. |
What is the use of belting? |
| A. | To hold the three cores and fillers in a tight assembly |
| B. | To hold the single core and fillers in a tight assembly |
| C. | Is used by only two core assembly |
| D. | Both (A) and (B) |
| Answer» B. To hold the single core and fillers in a tight assembly | |
| 130. |
What is the typical value of the capacitor used in ‘capacitor start capacitor run’ induction motor? |
| A. | 5 μ F |
| B. | 40 μ F |
| C. | 300 μ F |
| D. | 1000 μ F |
| Answer» D. 1000 μ F | |
| 131. |
What is the thickness of shims used to raise the motor? |
| A. | 0.5 mm – 5 mm |
| B. | 0.2 mm – 2 mm |
| C. | 0.1 mm – 1 mm |
| D. | None of these |
| Answer» C. 0.1 mm – 1 mm | |
| 132. |
What is the temperature limit for the storage of machines at site before installation? |
| A. | Temperature above + 25 °C |
| B. | Temperature above + 5 °C |
| C. | Temperature less than 10 °C |
| D. | Temperature above 15 °C |
| Answer» E. | |
| 133. |
What is the slip equation using stroboscopic method? |
| A. | Slip = (apparent rpm / 120 ) * pair of poles |
| B. | Slip = (apparent rpm / 60 ) * pair of poles |
| C. | Slip = (apparent rpm / 150 ) * pair of poles |
| D. | Slip = (apparent rpm / 30 ) * pair of poles |
| Answer» C. Slip = (apparent rpm / 150 ) * pair of poles | |
| 134. |
What is the residual voltage in VT? |
| A. | Vector sum of three line to line voltages |
| B. | Vector sum of three line to earth voltage |
| C. | Vector sum of three phase voltage |
| D. | None of these |
| Answer» C. Vector sum of three phase voltage | |
| 135. |
What is the range of MHV substations? |
| A. | All voltages above 1000 V AC |
| B. | Voltages between 1kV and 33 kV |
| C. | Between 33 kV and 110 kV |
| D. | 220 kV and 400 kV |
| Answer» C. Between 33 kV and 110 kV | |
| 136. |
What is the purity of electrically graded aluminium? |
| A. | 95 % |
| B. | 98.3 % |
| C. | 99.5 % |
| D. | 97.5 % |
| Answer» D. 97.5 % | |
| 137. |
What is the preferred value of DC test voltage for site? |
| A. | 104 % of the routine factory AC test voltage |
| B. | 65 % of the routine factory AC test voltage |
| C. | 1.6 % of the routine factory AC test voltage |
| D. | 75 % of the routine factory AC test voltage |
| Answer» B. 65 % of the routine factory AC test voltage | |
| 138. |
What is the possible cause if the slip ring induction motor fails to start? |
| A. | Open rheostat |
| B. | Overload |
| C. | Brushes do not touch collector rings |
| D. | Only (b) and (c) |
| E. | All of these |
| Answer» F. | |
| 139. |
What is the polarization index value for a class A type insulation? |
| A. | 1.5 |
| B. | 2.0 |
| C. | 2.5 |
| D. | Less than 1 |
| Answer» B. 2.0 | |
| 140. |
What is the permitted noise level in db for a 500 kW motor running at a speed of 1500 rpm? |
| A. | 60 db |
| B. | 75 db |
| C. | 90 db |
| D. | 55 db |
| Answer» D. 55 db | |
| 141. |
What is the permissible value of temperature of the machine parts while drying out by resistance method? |
| A. | 65 °C |
| B. | 70 °C |
| C. | 80 °C |
| D. | 45 °C |
| Answer» D. 45 °C | |
| 142. |
What is the minimum life span of a galvanised steel structure? |
| A. | 15 years |
| B. | 25 years |
| C. | 40 years |
| D. | 80 years |
| Answer» D. 80 years | |
| 143. |
What is the minimum deionisation time necessary for auto reclosing in a circuit breaker if the voltage of transmission line is 132 kV? |
| A. | 5 cycles |
| B. | 14 cycles |
| C. | 9 cycles |
| D. | 13 cycles |
| Answer» D. 13 cycles | |
| 144. |
What is the maximum temperature of the electrolyte in case of nickel cadmium battery? |
| A. | 10 ° |
| B. | 25 ° |
| C. | 46 ° |
| D. | 60 ° |
| Answer» D. 60 ° | |
| 145. |
What is the maximum temperature limit up to which class E insulation can be used? |
| A. | 120 °C |
| B. | 180 °C |
| C. | 50 °C |
| D. | 90 °C |
| Answer» B. 180 °C | |
| 146. |
What is the maximum rated output for an engine driven synchronous generator? |
| A. | 10 MW |
| B. | 20 MW |
| C. | 50 MW |
| D. | 100 MW |
| Answer» C. 50 MW | |
| 147. |
What is the maximum permissible voltage drop that can be sustained while starting an electrical rotating machine? |
| A. | 15 – 20 % of the rated voltage |
| B. | 20 – 25 % of the rated voltage |
| C. | 5 – 10 % of the rated voltage |
| D. | 0 – 5 % of the rated voltage |
| Answer» B. 20 – 25 % of the rated voltage | |
| 148. |
What is the main cause of harmful vibrations in the machine? |
| A. | Mechanically unbalanced rotor |
| B. | Bent or cracked shaft |
| C. | An excessively pulsating load |
| D. | All of these |
| E. | None of these |
| Answer» E. None of these | |
| 149. |
What is the main cause of noise in the transformer? |
| A. | Magnetostriction |
| B. | Mechanical vibration of the tank |
| C. | Mechanical vibration due to lamination |
| D. | Only (a) & (c) |
| E. | All of these |
| Answer» F. | |
| 150. |
What is the main application of single phase circuit breaker? |
| A. | In power generating station |
| B. | On the roof of coach |
| C. | Both (a) and (b) |
| D. | On the distribution system |
| Answer» C. Both (a) and (b) | |