HIGH VOLTAGE MANAGEMENT LEVEL EXIT EXAM QUESTIONS AND ANSWERS 1.0

• The normal system voltage is not exceed ________ KV as per marine high voltage regulations

1. 5
2. 10
3. 15                    *
4. 25

• The electrical field strength at which the breakdown occurs in the material is called its ______

1. Breakdown voltage
2. Di-electric strength               *
3. Tri-electric strength
4. Breakdown strength

• ____________ are used for resilient flooring conditions and pathways In high voltage panels.

1. Insulation gloves
2. Insulation mats                   *
3. Insulation tapes
4. Insulation helmets

• _________ type of work procedure involves electrical installation that are not live or not changed

1. Live working
2. Dead working                  *
3. Working in the vicinity of live parts
4. None of the above

• After the 2010 Manila amendments, the _______ has made training on HV systems mandatory for senior engineering staff who work in electrical power plants above 1000 volt

1. SOLAS
2. STCW                          *
3. MARPOL
4. IMO

• PI test is conducted for low voltage generators

1. True
2. False                      *

• Air blast circuits breakers are preferred for

1. Short duty
2. Intermittent duty
3. Repeated duty                        *
4. All of these

• ARC interruption is done by ______

1. High resistance interruption
2. Low voltage interruption
3. Both A and B                           *
4. None of the above

• Desired tripping of a circuit breaker is

1. Manually
2. Automatically                  *
3. That is should give warning
4. None of these

• What is the polarisation index ?

1. Ratio of 10 min resistance to one min insulation resistance
2. Ratio of 1 min resistance to 10 min insulation resistance
3. Ratio of 5 min resistance to 25 min insulation resistance
4. None of the these

• The direction of mechanical force experienced on a current carrying conductor placed in a magnetic field is given by

1. Fleming’s left hand rule                 *
2. Fleming’s right hand rule
3. Helix rule
4. Corkscrew rule

• Which of the insulating medium can be used to fill up sphere gaps

1. Liquid insulation (transformer oil)
2. Solid insulator (polyester, paper)
3. Gas insulation (SF₆ , N₂ , CO₂ , CCL₂F₂)
4. Any of the above             *

• Fuse protection is used for current ratings up to _________

1. 10 A
2. 20 A
3. 50 A
4. 100 A                          *

• The high voltage circuit must be de-energized and grounded with a grounding stick before touching it or before leaving it unattended and exposed

1. True                         *
2. False

• Which of the following circuit breakers has high reliability and minimum maintenance ?

1. Air blast circuit breakers
2. Circuit breaker with SF₆ gas                                       *
3. Vacuum circuit breaker
4. Oil circuit breaker

• Overvoltage protection is recommended for _______

1. Hydro-electric generator                          *
2. Steam turbine generator
3. Gas turbine generator
4. All of the above

• MCB protects a circuit from

1. Short circuit
2. Over load only
3. Both short circuit and overload                            *
4. None of the above

• Phenomenon of ARC interruption takes place at ____

1. Zero voltage
2. Zero current                       *
3. High current
4. High voltage

• What happens in the arc extinction using high resistance method ?

1. Arc resistance is decreased with time
2. Arc resistance is increased with time                                *
3. No change it remains the same
4. Arc resistance is kept zero

• The arcing contacts in a circuit breaker are made of _________-

1. Copper Tungsten alloy                  *
2. Porcelain
3. Electrolytic copper
4. Aluminium alloy

• Under fault conditions, the higher voltages and fault current levels can develop small quantities of energy

1. True
2. False                           *

• ____________ contains the shipyard’s description of operations regarding the vessel’s HV equipment

1. Preliminary operation manual                          *
2. High voltage operation manual
3. Performance manual
4. Equipment manual

• The induced voltage across a stationary conductor in a steady magnetic field is zero

1. True                      *
2. False

• A low voltage protection circuit is used in electric motor starting equipment to

1. Trip circuit contractor when the motor over speed due to low voltage
2. Trip circuit contractor when the motor develops short circuit due to low voltage
3. Allow the motor to restart automatically on restoration of voltage without manual resetting
4. Prevent motor from restarting automatically                         *

• In air blast circuit breakers, the pressure of air is of the order of

1. 100 mm Hg
2. 1 kg/cm²
3. 20 to 30 kg/cm²                               *
4. 200 to 300 kg/cm²

• What is the primary means by which an electrical maintenance worker is protected from electrical hazards while performing work on an electrical circuit ?

1. Shutting down the necessary equipment
2. Using the appropriate personal protective equipment
3. Posting of safety warning signs
4. Performing a lock out/ tag out procedure                               *

• The supply voltage to portable tools and appliances should not exceed 1000 volts

1. True
2. False                     *

• Surge voltage originate in power systems due to ________

1. Lightning
2. Switching operations
3. Faults
4. Any of the above                         *

• Which of the following technique is used for the measurement of AC high frequency voltages ?

1. Peak voltmeter               *
2. Series resistance micrometer
3. Resistance potential divider
4. Any of the above

• Large capacity generators are manufactured to generate power at

1. 440 V
2. 6.3 to 10.5 KV                  *
3. 132 KV to 220 KV
4. 400 KV

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