MTA Helper Exam 4612 Questions and
Answers
Question 1
a non-inductive carbon resistor consumes 50 Watts when connected across a 120 volt
DC source if it is connected across a 120 volt AC source the power consumed by the
resistor will be nearest to?
Correct Answer
50 Watts
Question 2
before conducting an insulation resistance test on large machines with a mega it is
considered good practice to ground the windings for about 15 minutes immediately
prior to the test the most likely reason for this is to?
Correct Answer
remove static electricity which may have accumulated during the running of the
machine
Question 3
it is desire to operate a 6 volt lamp from 120 volt AC source this can be done with the
least waste Power by using a?
Correct Answer
Step Down Transformer
Question 4
the conductors of the two wire number 12 armored cable used in an ordinary lighting
circuit are?
Correct Answer
solid and rubber insulated
Page 1 of 55
,Question 5
What is the total length of Electrical conduit that must be run 14'6" 21'3" 6'0 22'9"
Correct Answer
64'6"
Question 6
the electrolyte in a lead storage battery is?
Correct Answer
sulfuric acid
Question 7
The number of 120 volt light Bulbs that should normally be connected in series across
a 600 volt Electric line is?
Correct Answer
3
Question 8
to smooth out the ripples present in rectified AC the device commonly used is a?
Correct Answer
filter
Question 9
a 1/2 ohm a 2 ohm a 5 ohm and a 25 Ohm resistor are connected in series to a power
source the resistor which will consume the most power is the?
Correct Answer
25 ohm
Page 2 of 55
,Question 10
the main reason for using copper tips and soldering irons is because copper?
Correct Answer
is a good heat conductor
Question 11
The device indicated by the letter s is?
Correct Answer
Diode
Question 12
Transit workers are caution not to leave tools on scaffolding the most reason for this
rule is to?
Correct Answer
avoid a safety hazard
Question 13
a rheostat is used in the field Circuit of a shunt generator to control the?
Correct Answer
generator voltage
Question 14
the number 6-32 for a machine screw specifies the diameter and the?
Correct Answer
the number of threads per inch
Page 3 of 55
, Question 15
in a house bill circuit the push button for ringing the bell is generally connected in the
secondary of the Transformer feeding the Bell one reason for doing this is to?
Correct Answer
keep line voltage out of the push button circuit
Question 16
a new helper is told by an experience helper that he is not doing a particular job
properly the best reason for the new helper to give this advice do consideration is
that the other helper?
Correct Answer
has more experience on the job
Question 17
the negative return for the car motors is through?
Correct Answer
one running rail
Question 18
when working your acid storage batteries extreme care should be taken to guard
against Sparks mainly because a spark May?
Correct Answer
cause and explosion
Question 19
the material discharged by a carbon dioxide fire extinguisher should not be handled
because it?
Correct Answer
can cause a frostbite
Page 4 of 55
Answers
Question 1
a non-inductive carbon resistor consumes 50 Watts when connected across a 120 volt
DC source if it is connected across a 120 volt AC source the power consumed by the
resistor will be nearest to?
Correct Answer
50 Watts
Question 2
before conducting an insulation resistance test on large machines with a mega it is
considered good practice to ground the windings for about 15 minutes immediately
prior to the test the most likely reason for this is to?
Correct Answer
remove static electricity which may have accumulated during the running of the
machine
Question 3
it is desire to operate a 6 volt lamp from 120 volt AC source this can be done with the
least waste Power by using a?
Correct Answer
Step Down Transformer
Question 4
the conductors of the two wire number 12 armored cable used in an ordinary lighting
circuit are?
Correct Answer
solid and rubber insulated
Page 1 of 55
,Question 5
What is the total length of Electrical conduit that must be run 14'6" 21'3" 6'0 22'9"
Correct Answer
64'6"
Question 6
the electrolyte in a lead storage battery is?
Correct Answer
sulfuric acid
Question 7
The number of 120 volt light Bulbs that should normally be connected in series across
a 600 volt Electric line is?
Correct Answer
3
Question 8
to smooth out the ripples present in rectified AC the device commonly used is a?
Correct Answer
filter
Question 9
a 1/2 ohm a 2 ohm a 5 ohm and a 25 Ohm resistor are connected in series to a power
source the resistor which will consume the most power is the?
Correct Answer
25 ohm
Page 2 of 55
,Question 10
the main reason for using copper tips and soldering irons is because copper?
Correct Answer
is a good heat conductor
Question 11
The device indicated by the letter s is?
Correct Answer
Diode
Question 12
Transit workers are caution not to leave tools on scaffolding the most reason for this
rule is to?
Correct Answer
avoid a safety hazard
Question 13
a rheostat is used in the field Circuit of a shunt generator to control the?
Correct Answer
generator voltage
Question 14
the number 6-32 for a machine screw specifies the diameter and the?
Correct Answer
the number of threads per inch
Page 3 of 55
, Question 15
in a house bill circuit the push button for ringing the bell is generally connected in the
secondary of the Transformer feeding the Bell one reason for doing this is to?
Correct Answer
keep line voltage out of the push button circuit
Question 16
a new helper is told by an experience helper that he is not doing a particular job
properly the best reason for the new helper to give this advice do consideration is
that the other helper?
Correct Answer
has more experience on the job
Question 17
the negative return for the car motors is through?
Correct Answer
one running rail
Question 18
when working your acid storage batteries extreme care should be taken to guard
against Sparks mainly because a spark May?
Correct Answer
cause and explosion
Question 19
the material discharged by a carbon dioxide fire extinguisher should not be handled
because it?
Correct Answer
can cause a frostbite
Page 4 of 55
