1. Q. Why use fuses in an electrical circuit?
A. To protect circuits from overloads.
2. Q. Give two ways of identifying fuses in relation to electrical load -
(Capacity)?
A. 1. By Colour.
2. By Size.
3. Capacity on Fuse.
3. Q. What is a circuit breaker?
A. A device used as a means of starting or stopping an electrical current flow.
4. Q. Name two safety protection requirements that should be provided for
mains voltage soldering irons?
A. 1. They should be earthed or double insulated.
2. They should be protected by a RCD (residual current device)/E.L.C.B.
5. Q. When should screens be arranged around a welding job?
A. When there is a danger to others working nearby.
6. Q. Give two ways to make an electrically driven machine safe to do
maintenance work on?
A. 1. Lock out the switch with own lock.
2. Remove the fuses.
7. Q. Why is earthing of equipment necessary?
A. To ensure protective action results if the metal work becomes live due to
a
fault.
8. Q. Why not uses water on an electrical fire?
A. Water is an electrical conductor and could cause a short circuit.
9. Q. Give two reasons for keeping power cables off the floor?
A. 1. Damage to Cables.
2. A Tripping Hazard
10. Q. Give two methods of protecting yourself from risk of shock to earth which
do not involve electrical trip devices?
A. 1. Use rubber mats.
2. Wear rubber boots.
11. Q. Give two hazards other than personal shock and equipment failure, which
may result from faulty electrical equipment?
A. 1. Fires.
2. Explosion.
12. Q. What precautions must you takes when testing live equipment?
A. Use only a proper insulated test set.
13. Q. How is a double insulated appliance identified?
A. A double insulated appliance is marked with two squares one inside
the other.
14. Q. Name two prime areas in an electrically powered tool, which should be
examined for possible damage before the tool is used?
A. 1. The Plug.
2. The Power Cable.
3. Entry point of cable to appliance.
15. Q. Must all portable electric power tools be earthed?
A. Yes, unless they are of the approved double insulated type.
16. Q. Give two reasons why a portable electric power tool should not be
connected to a light socket?
A. 1. It will not be earthed.
2. It may cause an overload.
17. Q. What causes Static Electricity?
A. Movement and friction of materials which may be solids, liquids
or gases.
18. Q. Static Electricity is produced when electrons are displaced in the surface of a
material. Give two common causes of a build up of a static electricity charge?
A. 1. The flow of solids.
2. The flow of liquids.
3. The flow of gas through an orifice.
4. The wearing of synthetic fibre clothing.
19. Q. What is the basic thing that should be done if there is a risk of Static
Electricity builds up?
A. Earth the relevant equipment.
20. Q. What is essential to ensure low voltage electrical appliances are properly
used?
A. They must be fitted with discriminating plugs to prevent them being
plugged in to mains.
21. Q. What is the recommended maximum voltage for portable hand-lamps,
used in damp or confined spaces?
A. They must not be more than 25 Volts AC or 50 Volts DC.
22. Q. If a fault develops in a portable electric tool, what action should you take?
A. Cease to use it, and report it to your superior.
23. Q. What is the danger of metal lamp holders?
A. They may become live with the risk of electrocution.
24. Q. When taking an electrical cable across a gang-way, what precautions would
you take?
A. Carry it safely overhead, or if on the floor, protect it with a suitable
cover.
25. Q. A person has received an electric shock and is still in contact with the live
circuit. What should you do?
A. Switch off the current if possible, remove from contact using a
non- conductor, and apply artificial respiration.
26. Q. What type of electrical equipment is necessary where there is a risk of fire
or explosion from fumes?
A. Equipment suitably classified for the exposure.
27. Q. Can one get burns from electricity?
A. Yes.
28. Q. What are the special requirements about hand tools used on electrical repairs?
A. They should be insulated.
29. Q. The process of interconnecting all exposed metalwork to eliminate voltage
differences (potential) between parts of the metalwork is called what?
A. Bonding
30. Q. Name four factors that increase the seriousness of electric shock?
A. 1. Voltage.
2. Moisture on the skin.
3. Damp surroundings.
4. A.C or D.C. Current.
5. Health of individual.
6. Magnitude of current.
31. Q. Name four hazards of working with electric power?
A. 1. Electric Shock.
2. Fire.
3. Explosion.
4. Arc Eye.
32. Q. In Health and Safety Legislation, how is high voltage defined?
A. Voltage exceeding:-
1. 1,000 volts A. C.
2. 1,500 volts D. C.
33. Q. Give four safety checks recommended before connecting an appliance to a
mains supply?
A. 1. Check appliance name plate voltage and frequency is matched to supply
potential.
2. Ensure socket and tool are switched off before plugging in.
3. Check cable and plug are in good condition.
4. Ensure that the cable is clear of the work.
34. Q. What are the four main factors which govern the seriousness of an electric shock?
A. 1. The amount of current flow.
2. The length of time of the current flow.
3. The personal sensitivity to shock current, due to dampness, or earth contact.
4. The general health of the person.
35. Q. Name four requirements of a battery charging room?
A. 1. It must be free of smoking or naked flames.
2. It must have adequate ventilation.
3. It must have adequate suitable fire extinguishers.
4. It must have suitably classified electrical fittings.
36. Q. Give four design requirements of a portable lead lamp?
A. 1. Use a proper insulated holder.
2. Use a reliable switch.
3. Have a substantial enclosure around the bulb.
4. Ensure that the voltage meets regulation requirements.
37. Q. Name four main requirements of an Electric Isolation Request Permit?
A. 1. To nominate the precise plant to be isolated.
2. To nominate a date and time for the isolation.
3. To nominate the type of isolation required i.e. Fuses or Cables etc.
4. To get an acknowledgement when the isolation is complete.
5. To De-isolate and restore power to the equipment when safe to
do so.
38. Q. Where a high voltage transformer or switchgear outside a building is to be
protected by fencing what minimum height of fence is required?
A. 2.4 metres (8 feet approx.)
39. Q. Which Portable Electric Tools need not meet the requirements that the
metal work be efficiently earthed?
A. "All Insulated" and "Double Insulated" Tools to approved standards.
40. Q. What is the advantage of earthing the centre point of a portable 110 Volt
Transformer?
A. It limits the voltage to earth to 55 Volts, thus decreasing the electric shock
potential below the known fatal level.
41. Q. If one buys an electric drill with a kite mark and a double square mark on it,
What do these marks mean?
A. The Double Square means it is Double Insulated and the Kite Mark means it
is to a British Standard.
42. Q. Which of the following types of conduit are suitable for installation in
extreme cold environments (a) Flexible Conduit, (b) Aluminium Conduit,
(c) Plastic Conduit, (d) Steel Conduit?
A. a, b, and d. Plastic Conduit may become brittle and crack.
43. Q. When an Earth Leakage Circuit Breaker is combined with an Excess Current
Operated Circuit Breaker, what protection is given to the circuit?
A. The circuit is protected against Earth Faults and Overloads.
44. Q. Name four significant requirements for voltage detectors used for testing
whether a circuit is live?
A. 1. They should be properly designed.
2. They should have well shrouded probes.
3. They should have adequately insulated handles.
4. They should have current limiting resistors.
45. Q. What is flameproof electrical equipment?
A. Electrical equipment which can be used with safety in a flammable atmosphere without the risk of causing a fire.
46. Q. Name 4 steps in protecting a heavy underground electric cable?
A. 1. Lay the cable in plastic conduit.
2. Pack around the conduit with sand.
3. Cover the sand over the cable with flagstones.
4. Post ample warning notices along route of cable.
47. Q. You may find two colour coding schemes in use when you go to wire a
single-phase 13-amp plug. What are the colour codes for Live, Neutral, and
Earth in these two schemes?
A. Live:- Brown (New); Red (Old)
Neutral:- Blue (New); Black. (Old)
Earth:- Green/Yellow (New); Green (Old)
48. Q. Current electricity legislation and guidance requires that all electrical
equipment and installations shall at all times meet eight requirements so as
to prevent danger. Name four of the eight?
A. 1. Properly designed
2. Properly constructed.
3. Properly installed.
4. Properly maintained.
5. Properly protected.
6. Properly used.
7. Protected from ingress of moisture or of particles
8. Protected from foreseeable impacts.
49. Q. In the current electricity legislation and guidance the word danger means the
risk of personal injury from five electricity related events. Name four of the five?
A. 1. Electric shock.
2. Electric burn.
3. Electrical explosion or arcing.
4. Fire or explosion caused by electricity use.
5. Mechanical movement of electrical driven equipment.
50. Q. Give four dangers associated with lead acid accumulators?
A. 1. Very high currents may be produced.
2. Hydrogen Gas is produced while being recharged.
3. Danger of acid spills.
4. They tend to be very heavy and awkward to handle.
51. Q. Poor lighting results in 4 well identified undesirable consequences. Can you
name them?
A. 1. Fatigue.
2. Errors.
3. Stress.
4. Accidents.
52. Q. The maintenance of a well-designed lighting system at its peak efficiency can
be dependent on four essential maintenance tasks. Can you name them?
A. 1. Replacement of spent bulbs.
2. Correct bulb replacement.
3. Regular cleaning of lamps.
4. Regular cleaning of windows.
53. Q. The degree of illumination required to enable any specific task to be performed
with relative ease and safety depends upon five factors. Name four?
A. 1. Size of object.
2. Speed of movement.
3. Duration of task.
4. Brightness contrasts.
5. Colour.
54. Q. What is the name of the effect that makes a rotating shaft appear
stationary under certain lighting conditions?
A. Stroboscopic Effect.
55. Q. The electricity regulations refer to an electro-mechanical device capable of
making, carrying and breaking currents under normal and abnormal circuit
conditions such as those of a short circuit, what is this device called?
A. A circuit breaker.
56. Q. If a piece of electrical apparatus is designed and constructed such that,
even under fault conditions, the electrical energy within the circuits is less
than the minimum ignition energy of the flammable atmosphere in which it
is to operate. How would it be rated / classified?
A. Intrinsically Safe.
57. Q. What is the purpose of Insulation Resistance Tests?
A. To ensure that phase and neutral conductors are not 'leaking' to earth.
58. Q. What is the purpose of Continuity Resistance Tests?
A. To ensure that where fitted ring cables (such as socket circuits)
are intact.
59. Q. What is the purpose of Earth Fault Loop Impedance (EFLI) tests?
A. They are carried out to verify that earthing characteristics
are satisfactory.
60. Q. What is the purpose of checking Tripping times?
A. To see if the tripping time of residual current devices (RCD) are within
acceptable time limits.
61. Q. What is the purpose of protective devices in electrical circuits?
A. To protect against overload
To protect against faults.
62. Q. Name two types of fire extinguisher that can be used on an electrical fire as
described in I.S. 291: 2002?
A. 1. Dry Powder
2. CO2
3. FM 200.
63. Q. I.S. 291: 2002 list two types of extinguisher that should not be used in
electrical fire! What are these?
A. 1. Water
2. Foam
64. Q. Within the context of electrical safety what is the meaning of the term “isolation”?
A. "Isolation" means the disconnection and separation of electrical equipment
from every source of electrical energy in such a way that the disconnection
and separation is secure.
65. Q. Give the three ways in which electricity may cause death?
A. 1. Direct action (shock) on heart and respiratory organs.
2. Burns.
3. By the involuntary action of the body as a result of shock. e.g.
Fibrillation of the Heart.
66. Q. Flameproof equipment is designed for a number of specific gas and vapour
groupings namely Group 1, 2A, 2B, 2C. This is because certain gases and
vapours have properties requiring design to higher standard. Which group
covers natural gas being the lowest standard requirement?
A. Group 1.
67. Q. Name three types of electrical equipment which may be used in a Zone 1
classification?
A. 1. Intrinsically Safe Equipment.
2. Flame Proof Equipment.
3. Pressurised Equipment.
4. Powder Filled Equipment.
5. Increased Safety Equipment.
6. Encapsulated Equipment.
68. Q. What type of electrical equipment is required in Zone O classification?
A. Intrinsically Safe Equipment.
69. Q. What three steps should be taken after the operation of a Residual Current
Device (R.C.D.)?
A. 1. Check the appliance connected to the circuit breaker for fault
or defect.
2. Correct the fault or defect.
3. Re-set the circuit breaker in the positive mode.
70. Q. Current legislation and guidance dealing with electrical safety requires that
every circuit in excess of 125 volts supplying or intended to supply portable
or transportable apparatus must be protected by what?
A. A mains Residual Current Device (RCD) to cut off power if leakage current to earth should exceed 30 milli amps.
71. Q. It is a legal requirement that a circuit supplying a socket outlet must be
protected by a residual current device having a tripping current not
exceeding 30 milliamperes (mA). How does a residual current device
operate?
A. Leakage from the electrical circuit will cause an imbalance in the current flowing from the phase conductor and returning to the neutral conductor, if
this exceeds a pre-determined value usually 30 mA the power will be disconnected by the device.
72. Q. What is a multiple lock out clasp used for, and what does the multiple
lockout clasp ensure?
A. 1. To allow each worker to fix his own lock on an isolated item of
equipment
2. The isolated item of equipment can not be made live until all workers have withdrawn and removed the locks.
73. Q. To aid the choice of electrical equipment for use in areas where flammable
gas or vapours may be present such areas are classified according to the
likelihood of the areas having flammable atmospheres. (a) How are such
areas referred to, and (b) what is the highest risk area?
A. (a) Zone 0, Zone 1, Zone 2.
(b) Zone 0
74. Q. To aid the choice of electrical equipment for use in areas where flammable
dusts may be present such areas are classified according to the likelihood of
the areas having flammable atmospheres. How are such areas referred to
and what is the highest risk area of these?
A. (a) Zone 20, Zone 21, Zone 22.
(b) Zone 20.
75. Q. Electrical equipment for use in flammable atmospheres has to reflect its
suitability for use in relation to the specific gas and vapour groupings which
are designated as Group 1, 2A, 2B, 2C. This is because certain gases and
vapours have properties requiring different design standards. To what
group does (a) Petrol Vapour and (b) Gas encountered in coal mines
belong?
A. (a) Group 2A.
(b) Group 1.
76. Q. How is “high voltage” defined in Current legislation and guidance dealing
with electrical safety ?
A. “High voltage" means any voltage exceeding -
(a) 1000 volts alternating current,
(b) 1500 volts direct current.
77. Q. The National Rules for Electrical Installations are published from time to
time. Who produces these rules?
A. The Electro-Technical Council of Ireland (ETCI).
78. Q. The “National Rules for Electrical Installations” frequently refer to IP
Ratings for electrical equipment and fittings. What does IP stand for, and
what do the two numbers that follow it refer to?
A. IP Stands for Index of Protection and is followed by two numerals i.e. IP44.
The first numeral indicates the level of protection against physical contact
with live parts of the fitting and the degree that the equipment is protected
against solid foreign bodies intruding into an enclosure. The second numeral indicates the level of protection against moisture penetration.
79. Q. (a) What is bonding? and (b) Why is it important?"
A. (a) Bonding is the process of interconnecting all exposed metalwork to eliminate voltage differences (potential) between parts of the metalwork.
(b) It reduces the risk of electric shock and the risk of static electricity build up and is particularly important in livestock buildings, milking parlours and in bathrooms, etc.
80. Q. The intention of periodic testing of the fixed wiring is to ensure that the
system is safe for use and has not suffered damage or severe deterioration.
List three tests that should be periodically undertaken on an electrical system
A. 1. Insulation resistance tests
2. Continuity resistance tests
3. Earth fault loop impedance (EFLI) tests
4. Tripping times of residual current devices (RCD).
81. Q. The risk of damage and the resultant injury from portable electrical
equipment is higher than that of fixed appliances due to its portable
nature. Before the first use during a working day, staff should make a quick
visual check of the equipment they are to use or is sited in their area. List six
types of situations that should be reported?
A. 1. Damage to the case of the equipment
2. Damage to the cabling
3. Damage to the plug
4. Evidence of wires pulling out of the case or plug
5. Blackening of the socket
6. Evidence of a smell associated with hot burning plastic, rubber etc.
82. Q. Name six types of protective devices used in an electrical circuit?
A. 1. Fuse
2. Miniature Circuit breaker (MCB)
3. Residual Current Device (RCD)
4. Residual Current Circuit breakers (RCCB)
5. Residual Current Circuit breakers with Overload protection (RCBO)
6. Magnetic Hydraulic Circuit breakers
7. Thermal Circuit breakers
8. Thermal Magnetic Circuit breakers.
83. Q. What is the difference between an overload current and a fault current?
A. An overload current is the application of a current greater than the design current resulting in the disruption of the circuit protective device.
Fault current is one generated by the rapid discharge of energy to earth
through a mechanical fault on a system resulting in a substantial rise and rapid disconnection by the circuit protective device.
84. Q. What two conditions can occur to the heart with electric shock, and what
action should be taken for each condition?
A. 1. Cardiac arrest, (the heart stops beating and blood is no longer
circulated). Treatment - immediate CPR.
2. Ventricular fibrillation, (the heart's electrical activity becomes
disordered) Treatment - use defibrillator followed by CPR.
85. Q. Name Eight Hazards associated with Manual Metal Arc Welding - (Electrical
Welding)?
A. 1. Electric Shock.
2. Burns.
3. Ultra-Violet Radiation.
4. Fire.
5. Fumes.
6. Arc - Eye.
7. Slag Chipping in Eyes.
8. Chemical Cleaning of Weld.
9. Trailing Cables.
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