HV - High Voltage Safety Officer & Switchgear Operations Exit Exam Questions - Set 3

Question 1

Which document contains the shipyard's description of operations regarding the vessel's High Voltage (HV) equipment?

Accepted Answer

A: Preliminary operation manual

Answer

B: High voltage operation manual

Answer

C: Performance manual

Answer

D: Equipment manual

Question 2

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

Accepted Answer

A: True

Answer

B: False

Question 3

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

Accepted Answer

D: Prevent motor from restarting automatically upon restoration of supply voltage

Answer

A: Trip circuit contactor when the motor over-speeds due to low voltage

Answer

B: Trip circuit contactor when the motor develops short circuit due to low voltage

Answer

C: Allow the motor to restart automatically on restoration of voltage without manual resetting

Question 4

In air blast circuit breakers, the compressed air pressure used for arc quenching is in the order of:

Accepted Answer

C: 20 to 30 kg/cm²

Answer

A: 100 mm Hg

Answer

B: 1 kg/cm²

Answer

D: 200 to 300 kg/cm²

Question 5

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

Accepted Answer

D: Performing a lockout / tagout (LOTO) and grounding procedure

Answer

A: Shutting down the necessary equipment only

Answer

B: Using personal protective equipment (PPE) alone

Answer

C: Posting safety warning signs

Question 6

What is the Polarisation Index (PI) in insulation resistance testing?

Accepted Answer

A: Ratio of 10-minute insulation resistance to 1-minute insulation resistance

Answer

B: Ratio of 1-minute insulation resistance to 10-minute insulation resistance

Answer

C: Ratio of 5-minute insulation resistance to 25-minute insulation resistance

Answer

D: Ratio of test voltage to leakage current after 1 minute

Question 7

The direction of mechanical force experienced by a current-carrying conductor placed in a magnetic field is determined by:

Accepted Answer

A: Fleming's left-hand rule

Answer

B: Fleming's right-hand rule

Answer

C: Helix rule

Answer

D: Corkscrew rule

Question 8

Which of the following insulating media can be used in sphere gaps and high-voltage test setups?

Accepted Answer

D: Any of the above

Answer

A: Liquid insulation (e.g., transformer oil)

Answer

B: Solid insulation (e.g., polyester, resin-bonded paper)

Answer

C: Gas insulation (e.g., SF6, N2, CO2, CCl2F2)

Question 9

Cartridge and rewireable fuse protection in general distribution circuits is typically used for continuous current ratings up to:

Accepted Answer

D: 100 A

Answer

A: 10 A

Answer

B: 20 A

Answer

C: 50 A

Question 10

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

Accepted Answer

A: True

Answer

B: False

Question 11

Which of the following circuit breakers provides high operating reliability and minimal maintenance requirements?

Accepted Answer

B: SF6 gas circuit breaker

Answer

A: Air blast circuit breaker

Answer

C: Vacuum circuit breaker

Answer

D: Bulk oil circuit breaker

Question 12

Which type of work procedure involves electrical installations that are completely de-energized, isolated, proven dead, and earthed?

Accepted Answer

B: Dead working

Answer

A: Live working

Answer

C: Working in the vicinity of live parts

Answer

D: Hot line working

Question 13

Following the 2010 Manila Amendments, which regulatory body made High Voltage (HV) system training mandatory for senior engineering staff on vessels with installations above 1,000 V?

Accepted Answer

B: STCW

Answer

A: SOLAS

Answer

C: MARPOL

Answer

D: ISPS

Question 14

Polarisation Index (PI) testing is typically required and conducted for standard low-voltage (< 1000 V) generators.

Accepted Answer

B: False

Answer

A: True

Question 15

Air blast circuit breakers are particularly preferred for applications requiring:

Accepted Answer

C: Repeated frequent duty

Answer

A: Short duty only

Answer

B: Intermittent duty only

Answer

D: DC traction sub-stations only

Question 16

High-voltage alternating current (AC) arc interruption is primarily achieved through:

Accepted Answer

C: Both A and B

Answer

A: High resistance interruption

Answer

B: Low resistance / zero-current interruption

Answer

D: Magnetic attraction only

Question 17

The desired protective tripping operation of a power circuit breaker under fault conditions is:

Accepted Answer

B: Automatically initiated by protective relays

Answer

A: Manually initiated

Answer

C: Warning buzzer alarm only

Answer

D: Delayed until watchkeeper reset

Question 18

Lower voltage systems supplied through step-down transformers from high-voltage systems must be protected against overvoltages. This is achieved by:

Accepted Answer

C: Both A and B

Answer

A: Direct earthing of the lower voltage system neutral

Answer

B: Appropriate neutral voltage limiters (surge arresters / spark gaps)

Answer

D: Increasing cable insulation thickness only

Question 19

In the arc extinction process using the high resistance method:

Accepted Answer

B: Arc resistance is increased with time

Answer

A: Arc resistance is decreased with time

Answer

C: Arc resistance remains strictly constant

Answer

D: Arc resistance is reduced to zero

Question 20

On high-voltage positive polarity conductors at elevated pressures, corona discharge visually appears as a:

Accepted Answer

A: Uniform bluish-white glowing sheath

Answer

B: Reddish glowing spot

Answer

C: Uniform greenish spot

Answer

D: Yellow pulsating flame

Question 21

SF6 gas exhibits high thermal heat capacity and thermal conductivity that can absorb arc energy without significant temperature rise.

Accepted Answer

B: True

Answer

A: False

Question 22

The heat produced at an electrical contact point owing to current flow is least affected by:

Accepted Answer

A: Temperature of the surrounding medium

Answer

B: Contact resistance

Answer

C: Magnitude of electric current flowing

Answer

D: Duration of current flow

Question 23

In a fully partitioned, air-insulated marine High Voltage switchboard, all sections shall be partitioned with respect to each other and surroundings so that they are arc-resistant.

Accepted Answer

B: True

Answer

A: False

Question 24

The High Voltage shore connection (cold ironing) supply plug is interlocked with the equipotential bonding conductor between ship and shore.

Accepted Answer

B: True

Answer

A: False

Question 25

When procedures involve the temporary removal of circuit main earths under a Sanction-to-Test, the earths are secured with working locks. The keys to these locks are:

Accepted Answer

A: Retained by the Authorised Person (HV) who removes and replaces the earth as requested

Answer

B: Retained by the Chief Engineer

Answer

C: Retained by the Electro-Technical Officer only

Answer

D: Kept inside the engine control room safety locker

Question 26

What are the primary hazards associated with an Arc Flash event in High Voltage systems?

Accepted Answer

D: All of the above

Answer

A: Sudden release of intense thermal energy, blinding light, and acoustic shockwaves

Answer

B: Severe burns and blast injuries that can be fatal even several meters away

Answer

C: Catastrophic structural equipment destruction and vaporized shrapnel

Question 27

Electrical alternating current (AC) power is generated and transmitted at high voltage primarily to:

Accepted Answer

B: Minimise I²R transmission losses and reduce conductor size

Answer

A: Safeguard against power theft

Answer

C: Reduce the capital cost of generator construction

Answer

D: Eliminate the need for circuit breakers

Question 28

When two diesel generator sets are running smoothly in parallel on the main switchboard during an engine room watch, what does this condition fundamentally imply?

Accepted Answer

A: Both generators have identical terminal voltage, system frequency, and phase sequence

Answer

B: Both diesels carry identical active kW, reactive kVAr, and line amperage at all times

Answer

C: Both diesels are operating at varying unsynchronized rotational speeds

Answer

D: Both generators are operating without voltage regulators

Question 29

In a 3-phase induction motor operating in normal motoring mode, the rotor rotates at a speed that is:

Accepted Answer

B: Slightly lower than the synchronous speed of the stator field

Answer

A: Equal to the synchronous speed of the stator rotating magnetic field

Answer

C: Higher than the synchronous speed of the stator field

Answer

D: Completely unrelated to the stator supply frequency

Question 30

For liquid-cooled static frequency converters on electric propulsion vessels, which additional monitoring arrangements must be provided?

Accepted Answer

D: All of the above

Answer

A: Stand-by coolant pump automatic start / alarm

Answer

B: Coolant conductivity monitoring (de-ionized water)

Answer

C: Coolant temperature and flow rate alarms

High Voltage Safety Officer & Switchgear Operations (HV) (Set 3)

Which document contains the shipyard's description of operations regarding the vessel's High Voltage (HV) equipment?

Questions in HV Set 3

Question Discussion & Notes

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