1 )
What do you mean by safety precaution ?
ANS : Safety
precaution means the prescribed rules for the safety of the personnel and
equipment that should be observed in electrical work , otherwise electric shock can be received.
2 ) How is the safety of an electrical
installation ensured ?
ANS :
The safety of an electrical installation is ensured by proper insulation , good
earthing and by providing fuses in the
circuits of that installation .
3 )
What is meant by being “ safety minded “ ?
ANS :
It means thinking of safety factor for every job .
4 )
What are the types of safety precautions to be observed ?
ANS :
Safety precaution to be observed are as follows :
1) Self
safety.
2) Equipment’s
and tools safety.
3) Safety
of working place.
5 ) Is
“ taking a chance “ in electrical work is ever justified ?
ANS : No .
6 ) Is
it permissible for a man to work on a job without a shirt ?
ANS : No .
7 )
What is electric shock ?
ANS :
Electric shock is the sudden convulsion of muscles with the feeling of pain
caused by the flow of electric current through the living body .
8 ) On
what factors does the severity of an electric shock depend ?
ANS :
1) Magnitude
of current flowing through the body.
2) Duration
of contact with liv parts .
3) Path
of the current through the human body .
4) The
type of supply (A.C or D,C ).
9 )
What are the effects of electric shock according to the flow of current through
the human body ?
ANS :
The effects of electric shock on human body :
a) Below
10 mA -> mild sensation but not
painful
b) 10
mA to 15 mA -> painful shock but
muscles will be in control
c) 15
mA to 20 mA -> muscles control
will be affected
d) 20
mA to 40 mA -> results muscle
contractions and breathing will be affected
e) 40
mA to 80 mA -> results rapid non sequential
series of contraction of heart muscles causing irregular heart beat and possible
death.
f)
Above 80 mA ->
results severe burns , muscle contraction and stoppage of heart beat causing certain death.
10 ) Is
single phase a.c supply voltage dangerous ?
ANS :
Yes, of course . in wet condition even 50 volt a.c may be dangerous to cause
electric shock.
11 )
Why is a.c voltage more dangerous than d.c voltage of same level ?
ANS :
Due to more peak value of a.c voltage than d.c voltage of same level a.c
voltage is more dangerous . whenever a person comes in good contact with a.c
voltage , he touches peak value ( √2 times the r.m.s.
value ) 100 times in a second and accordingly receives more electric shock .
12 )
When a man and a cow are standing at a same time near the earth electrode of a
large substation and a heavy earth fault has taken place then who will get more
shock and why ?
ANS :
The cow will get more shock due to its more step potential than that of the man
.
13 )
What are the different methods of artificial respiration ?
ANS :
The methods are :- 1) schafer’s method –
by laying the patient with his face downward requiring one operator , 2)
silvester’s method – by laying the patient with his face upwards requiring two
operators and 3) mouth to mouth method – a most effective method .
14 )
What should be the frequency of operation of artificial respiration ?
ANS :
It should be 15 times in a minute .
15 )
What special precautions are to be taken for mouth to mouth of artificial
respiration ?
ANS :
1) The
operator’s nose should be cleaned properly and he should not be a patient of
T.B or any infectious disease.
2) The
victim should be wrapped with blankets or hot water bottles should be used at
the feet.
16 )
Should the artificial respiration be stopped as soon as the patient starts
rebreathing ?
ANS :
The artificial respiration should not be stopped immediately after the patient
regains his respiration , it should be continued for some time .
17 )
Should any drink be given to the person receiving electric shock ?
ANS : No
drink should be given so long the person is unconscious but hot drink can be
given only after the person has gained consciousness.
18 )
What is temporary safety earthing ? where is it installed ?
ANS :
Before carrying out any repair & maintenance work of the electrical
equipment installation of temporary earthing of that equipment in order to
ensure the safety of the workmen and property is known as temporary safety
earthing .
Temporary safety
earthing is required for the high voltage overhead lines & high voltage
plant equipments.
19 )
When and why are rubber gloves and rubber shoes necessary ?
ANS :
For safe live line maintenance the person should be insulated from grounded
parts by means of rubber gloves and rubber shoes in order to eliminate the
contact current through his body to earth.
20 )
What procedure should be followed by a lineman during pulling a fuse , a
disconnect , a primary cut out or do anything which may cause flashing ?
ANS :
The workman should protect his eyes by wearing goggles or turning his head and
protecting his eyes and face with his arm
He should wear rubber
gloves and secure and secure himself to the pole with his safety belt.
21 )
Upto what limit towards the top of the pole the safety belt should be placed
around the pole ?
ANS :
Below 0.3 metre from the top of the pole .
22 )
What type of the ladder should be used in overhead line work ?
ANS :
Dry wooden ladder .
23 )
What should be the maximum horizontal distance from the pole / wall to the foot
of the ladder ?
ANS : Not
more than one quarter the length of the
ladder.
24 )
Should two men climb a pole at the same time ?
ANS :
No .
25 )
Where should the ground man be while the lineman is working on the pole ?
ANS :
At least 5 meters from the pole .