1) 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
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Answer
Explanation
Related Ques
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ANSWER: Circuits where storage batteries are not essential
Explanation:
No explanation is available for this question!
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2) How is the maximum discharge current calculated?
a. Maximum discharge current = (continuous load + rated voltage) / (short time load)
b. Maximum discharge current = (continuous load + short time load) / (rated voltage)
c. Maximum discharge current = rated voltage ( continuous load + short time load)
d. Maximum discharge current = (short time load + rated voltage) / (continuous load)
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Answer
Explanation
Related Ques
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ANSWER: Maximum discharge current = (continuous load + short time load) / (rated voltage)
Explanation:
No explanation is available for this question!
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3) Which element is used as the cathode in lead acid battery?
a. Sponge lead
b. Lead peroxide
c. Rubber mixed with lead
d. None of these
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4) 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
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5) Which charging method is employed for charging a Lead acid battery?
a. Tapper charging
b. Constant voltage charging
c. Two rate method of charging
d. All of these
e. None of these
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6) Which solutions are added into the lead acid battery?
a. Distilled water
b. Acid water solution
c. Transformer oil
d. Both (a) and (b)
e. All of these
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7) Which connection is preferred for connecting line tap changers to transformers?
a. 3 wire 3 phase AC system
b. 3 wire 2 phase AC system
c. 4 wire 3 phase AC system
d. All of these
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8) Which type of insulation is preferred if the maximum temperature is 130°?
a. Class A
b. Class B
c. Class E
d. Class F
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9) Which test is a special type of test performed on the transformers?
a. Partial discharge
b. Temperature rise test
c. Ratio and polarity test
d. Noise level test
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10) Which among these is not a type test performed on the current transformers?
a. Overvoltage inter turn tests
b. Short time current tests
c. Temperature rise tests
d. Error measurement
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11) Which among these is the essential part for a CT?
a. Insulation over the core by tape
b. Support porcelain or epoxy insulator
c. Synthetic resin or oil insulation
d. All of these
e. None of these
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12) What are the types of voltage transformers?
a. Electromagnetic potential transformers
b. Capacitor potential transformers
c. Inductor and resistor potential transformers
d. Only (a) and (b)
e. All of these
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13) 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
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14) Which among these is / are the abnormal operating conditions caused due to mechanical overloads?
a. Sustained overloads
b. Prolonged starting or locked rotor
c. Stalling
d. Only (a) and (b)
e. All of these
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15) What protection is preferred for preventing rotor faults?
a. Thermal relay
b. HRC fuses
c. Instantaneous over current relay
d. Differential protection
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16) Which among the following cooling system is employed for large machine?
a. Radial flow
b. Axial flow
c. Combined radial and axial cooling
d. Multiple inlet cooling
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17) What does S in ‘IP 11S’ represent?
a. Machine was tested when it was in running.
b. Machine was tested when not running condition.
c. Machine was tested at light load.
d. None of these.
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Answer
Explanation
Related Ques
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ANSWER: Machine was tested when not running condition.
Explanation:
No explanation is available for this question!
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18) Which cooling technique is employed for large turbo alternators?
a. Forced air cooling
b. Hydrogen cooling
c. Direct water cooling
d. Only (b) & (c)
e. All of these
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19) 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
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20) Which among the following factors affect the cost of motor?
i. Reliability and Availability
ii. Installation & Commissioning charges
iii. Running cost, KVAr
iv. Depression formula used
a. i & ii
b. ii, iii, iv
c. i, ii, iv
d. i, ii, iii & iv
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21) Which motor is preferred for cement industry?
a. Squirrel cage motor
b. Synchronous motor
c. Universal motor
d. DC series motor
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22) 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
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23) Which among these is a procedure used for the alignment of shaft?
a. Axial positioning of the shaft
b. Paralleling of the shaft axis
c. Centring of shaft axis
d. Only (a) and (c)
e. All of these
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24) 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
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25) Which among these are the properties of good grease?
i. Corrosion protection
ii. Viscosity
iii. Consistencies
iv. Mechanical stability
a. i & ii only
b. i & iii only
c. iii & iv only
d. i, ii, iii & iv
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26) 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
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27) Which among these tests are pre start test on an electrical machine?
i. Measurement of winding resistance
ii. On load tests
iii. Vibration tests
iv. High voltage tests
v. Tests on cooling system
a. i & iv only
b. i, ii & iv only
c. i, ii, iv & v only
d. i, ii, iii, iv, v only
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28) Which among these is the most significant for the operation of synchronous generator?
a. Frequency
b. Load
c. Terminal voltage
d. Only (a) and (b)
e. All of these
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29) Arrange the following according to the starting procedure of a synchronous Generator?
i. Start turbine auxiliaries
ii. Start boiler
iii. Roll the turbine
iv. Start the boiler auxiliaries
v. Keep the units as a spinning reserve
a. i, iii, v, iv, ii
b. i, iv, ii, iii, v
c. iv, i, ii, iii, v
d. iii, i, v, iv, ii
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30) 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
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Answer
Explanation
Related Ques
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ANSWER: Approximately 1 / 10 cycle higher than the bus frequency
Explanation:
No explanation is available for this question!
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31) 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
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32) Which among these is not a starting method of induction motor?
a. Direct on line starting
b. Ward Leonard method of starting
c. Thyristor starting control
d. Autotransformer starting
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33) Which among these tests is not a routine test performed on the circuit breakers?
a. Mechanical operation tests
b. Dielectric tests
c. Calibration tests
d. Mechanical endurance tests
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34) Which among the following type of ‘release’ is provided for low voltage circuit breaker?
a. Overload Release
b. Thermal overload release
c. Shunt Release
d. All of these
e. None of these
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35) Which medium is used in air blast circuit breaker?
a. Compressed air (20 – 30) kg f / cm2
b. Vacuum
c. SF6 gas
d. Air of atmospheric pressure
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