Electrical Installation Maintenance and Testing 6

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Electrical Engineering MCQ Question Papers: Campus Placement

Subject: Electrical Installation Maintenance and Testing 6

Part 6: List for questions and answers of Electrical installation Maintenance and Testing

 

Q1.What does ‘increasing In R with time indicates?

a) Healthy insulation

b) Poor insulation

c) Moderate insulation

d) None of these

 

Q2.What is dielectric absorption ratio?

a) (InR 30 s) / (InR 60 s)

b) (InR 60 s) / (InR 30 s)

c) (InR 10 s) / (InR 60 s)

d) (InR 60 s) / (InR 10 s)

 

Q3.Which among these tests is a DC test?

a) Polarisation index

b) Lightning impulse

c) Induced voltage tests

d) Switching voltage impulse

 

Q4.Which among these is the cause of sparking at brushes in DC motor?

a) Defective brushes

b) Defect in Commutator

c) Excessive load

d) All of these

 

Q5.Which material is used for the manufacture of brushes in DC motors?

a) Graphite

b) Lead

c) Copper

d) All of these

 

Q6.Which among these DC motor(s) is / are having lower full load torque?

a) Series motor

b) Shunt motor

c) Cumulative motor

d) Differential motor 

 

Q7.Which method is used for obtaining starting torque in a single phase induction motor?

a) Resistance split phase starting

b) Capacitor start capacitor run

c) Permanent split capacitor motor

d) All of these

 

Q8.Which type of rotor is used for single phase induction motor?

a) Wound rotor

b) Squirrel cage rotor

c) Both (A) and (B)

d) None of these

 

Q9.What is the main causes for the noise in the machine?

a) Magnetostriction

b) Aerodynamics

c) Bearing noise of rotating shaft

d) All of these

 

Q10.Which method is used to measure the speed of a synchronous machine?

a) Stroboscopic method

b) By tachometer

c) By measuring the frequency by means of frequency meter

d) All of these

 

Q11.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

 

Q12.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 

 

Q13.What is the application of ‘inverse torque power output type’ squirrel cage motor?

a) Conveyors

b) Fans

c) Centrifugal pumps

d) Machine tools

 

Q14.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

 

Q15.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

 

Q16.Which system present in the synchronous motor makes it costlier than Induction motor of the same size?

a) Damper windings

b) Additional excitation system

c) Additional field windings

d) None of these

 

Q17.What is filled in between fixed and rotating parts of a cryogenic generator?

a) Dry air

b) Hydrogen

c) Oxygen

d) None of these

 

Q18.Which power factor condition is not suitable for the operation of synchronous generator?

a) Leading power factor

b) Lagging power factor

c) Both (A) and (B)

d) None of these 

 

Q19.Why are the high voltage test conducted on the rotating machine?

a) To check the winding resistance

b) To check the insulation of windings

c) To check the maximum power rating of the machine

d) All of these

 

Q20.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 

 

Part 6: List for questions and answers of Electrical installation Maintenance and Testing

 

Q1. Answer: a

 

Q2. Answer: b

 

Q3. Answer: a

 

Q4. Answer: d

 

Q5. Answer: a

 

Q6. Answer: b

 

Q7. Answer: d

 

Q8. Answer: b

 

Q9. Answer: d

 

Q10. Answer: d

 

Q11. Answer: b

 

Q12. Answer: d

 

Q13. Answer: d

 

Q14. Answer: b

 

Q15. Answer: A

 

Q16. Answer: B

 

Q17. Answer: B

 

Q18. Answer: A

 

Q19. Answer: B

 

Q20. Answer: B