Electrotechnical Flashcards
In accordance with the Electricity at Work
regulations, when considering whether to work live a
responsible person should:
A: Carry out a risk assessment
B: Only work dead
C: Only work live
D: Do as the client demands
Right Answer: A
To identify and assess the risks involved and the
methods of controlling them.
The normal procedure for working on electrical
equipment should be which one of the following?
A: Dead working
B: Wearing insulated gloves
C: Using insulated tools
D: Live working
Right Answer: A
Dead working should be considered as the norm and
work on or near live conductors should rarely be
permitted
Test instruments used for working on electrical
systems should:
A: Be yellow in colour
B: Be less than 10 years old
C: Have non-insulated test probes
D: Have insulated test probes
Right Answer: D
To protect the user from electric shock whilst using
the instrument, i.e. handling the probes.
Under the Electricity at Work Regulations, live
working is considered:
A: As entirely acceptable
B: To be normally permitted
C: Only to be allowed in exceptional
circumstances
D: Never to be allowed
Right Answer: C
Extra controls must be employed, including training,
supervision and use of suitable tools and protective
equipment.
Which of the following would you use to replace the
fuse in a plug if fuses were NOT available?
A: A nail
B: A piece of silver paper
C: A bit of wire
D: None of the options listed
Right Answer: D
A fuse is often the main safety device in an electrical
circuit. A blown fuse must only be replaced by a fuse
of the correct type and rating.
To prove a circuit or equipment is dead after isolation
what is the FIRST activity in the sequence of events?
A: Make sure equipment is not working
B: Check between line and earth
C: Check that the voltage detector is working on
a proving device, known live source or in-
built test feature
D: Check between line and neutral
Right Answer: C
This will prove that that the voltage detector (such
as a two-pole voltage detector or proprietary test
lamp) is working, i.e. indicating voltage.
The nominal single phase voltage in the UK is?
A: 230 volts
B 240 volts
C: 415 volts
D: 400 volts
Right Answer: A
This is the nominal voltage for public electricity
supply systems within Europe.
When is live working permissible?
A: When the person carrying out the work is a
competent person
B: When it is unreasonable in all circumstances for the equipment to be made dead and
suitable precautions are taken
C: When the means of isolation cannot be
identified
D: When the person working on the equipment is wearing rubber gloves
Right Answer: B
This is a requirement under r.i4 of the EAW
Regulations. However, it does not mean that live
working is then ’safe’
Which of the following is not a requirement of low
voltage safe isolation practice?
A: Ensuring that the correct point of isolation is
identified
B The person carrying out the work is issued
with insulating gloves
C: A caution notice should be applied at the
point of isolation
D: The conductors are proved to be dead at the
point of work
Right Answer: B
Safe isolation practice refers to dead working. The
use of insulating gloves will generally only be
applicable to live working.
The specific effects on the human body of a major
electric shock are one of the following:
A: Dermatitis
B: Burns and cardiac arrest
C: Broken bones
D: Chest pains
Right Answer: B
The lowest level of electrical current which can harm
the human body is normally measured in:
A: Microamps
B: Kiloamps
C: Amps
D: Milliamps
Right Answer: D
Research has shown that a person is in serious
danger of a fatal electric shock at, or above,
approximately 30 milliamps.
With regard to the effect of electrical current on the
human body, one of the following is correct:
A: a 6 amp circuit breaker should prevent a
person receiving a fatal electric shock
B: a 3 amp fuse should prevent a personreceiving a fatal electric shock
C: a 30mA Residual Current Device (RCD)
should prevent a person receiving a fatal
electric shock.
D: a 5 amp rewireable fuse should prevent a
person receiving a fatal electric shock
Right Answer: C
An RCD is a mechanical switching device intended to
cause the opening of the contacts when the residual
current attains a given value under specified
conditions.
Where mains voltage is used to supply portable
equipment on a construction site, what additional
protection is required?
A: Step-down transformer
B Step-down generator
C: Cable avoidance tool
D Residual current device (RCD)
Right Answer: D
Reduced low voltage systems {e.g. 10 volt centre
point earthed) are strongly preferred in such
circumstances. Where only mains voltage (230 V)
equipment is available, however, a 30 mA RCD will
give additional protection against fatal electric shock.
What colour cable USUALLY signifies no volt power
supply on site?
A: Black
B: Red
C: Blue
D: Yellow
Right Answer: D
Yellow is the usual colour of cables, socket outlets,
plugs and transformers etc which are used with a 110
volt supply.
A portable electric generator on site has two power
outlets, no volts and 230 volts. What colour would
the no volt outlet be?
A: Black
B: Yellow
C: Red
D: Blue
Right Answer: B
Yellow is the usual colour of cables, socket outlets,
plugs and transformers etc which are used with a no
volt supply.
Where there is no local means of isolation for
equipment or circuits to be worked on, which of the
following is the preferred method of isolation?
A: Isolation of the main switch or DB switch-
disconnector
B Isolation of the individual circuit breaker or
fuse
C: Pulling out the distributor’s cut-out fuse
D: Disconnecting the individual circuit from the
DB
Right Answer: A
Isolating the whole installation or distribution board
is the safest method.
What action should you take if a workmate gets an
electric shock?
A: Phone the electricity board immediately
B: Dial 999 and ask for the fire brigade
C: Cut off the power and call for help
D: Try to pull them to safety
Right Answer: C
If you can switch the power off, the electric hazard
will be removed. First aid assistance will then
probably be required. Do not touch someone who is
still in contact with live electrical cables as you could
also receive an electric shock.
A residual current device is designed to operate in
the event of one of the following:
A: Overload
B: Earth fault
C: Lightning strike on the supply
D: Short-circuit
Right Answer: B
An RCD provides additional protection against the
risk of electric shock.
Electrical installations on construction sites should be
periodically inspected and tested:
A: Every 3 months
B: Every year
C: Every 6 months
D: Every month
Right Answer: A
Three monthly inspections of construction site
installations are recommended in IET Guidance Note
The maximum AC voltage which the human body
can withstand without long term physiological
effects in dry conditions is:
A: 110 volts
B 230 volts
C: 50 volts
D 400 volts
Right Answer: C
Regarded as a non-fatal voltage level.
Which of the following statements is true with
regard to the dangers of electricity?
A: Electricity is perfectly safe so long as you
wear cotton gloves
B: Electricity is only dangerous if you are not
wearing wellington boots
C: Electricity is only dangerous in wet weather
D: Electricity is dangerous at any time because
you cannot tell by looking at a cable whether
or not it is live
Right Answer: D
The features which make electricity so dangerous are
that you cannot see, hear or smell it. It can give you
a very unpleasant surprise. Always assume that
cables are live.
What is the most serious effect that electric shock
can have if you come into contact with a live part?
A: The electric current can cause a slight
tingling in the fingers
B The electric current can cause burn marks on
the fingers
C: The electric current can cause the heart to
stop, resulting in death
D: The electric current can cause the finger
muscles to twitch
Right Answer: C
Contact with live electrical parts can be fatal. If you
do not know otherwise, always assume that
electrical parts are live.
Your job involves you working near to hanging
electrical cables which have bare ends. What should
you do?
A: Touch the cables to see if they are live
B: Carry on working, as there shouldn’t be a
problem
C: Inform your supervisor and keep well away
D: Attempt to push the cables back into the ceiling void so that you can start work
Right Answer: C
You must always assume that exposed cables are
live until you know they are not. Contact with live
electrical cables can kill.
For all live working activities it is necessary to:
A: Carry out a risk assessment as required by
the EAW Regulations.
B: Wear rubber gloves only
C: Be accompanied
D: Keep your fingers crossed
Right Answer: A
