Electrical Theory Test (Trade Knowledge) – Q’s And A’s
Voltmeter Right Ans - A high resistance is connected in series with the
internal coil of a galvanometer to make?
If a transformer ratio is 20/1, what does it mean for the secondary? Right
Ans - The primary voltage is 20 times greater than that of the secondary.
If a motor enclosure is designed to contain sparks or flashes that could ignite
surrounding vapors or gases, then the enclosure is considered to be which of
the following: Right Ans - Ventilated
The output of a 3-phase transformer is measured in what units? Right Ans -
Amperes
In order to change the rotation of a DC series motor, what must be done?
Right Ans - F1 and F2 must be reversed.
What does Bonding do? Right Ans - Controls the load on the system
installation
A meter used to measure both AC and DC voltage and current is known as?
Right Ans - Multimeter
What material is used on conduits inside and outside of a box? Right Ans -
Couplings
If a transformer has a voltage step-down from 117 volts to 6 volts then the
ratio of the transformer is equal to what? Right Ans - 1: 19, 5
If the power factor of a circuit is increased, then what occurs? Right Ans -
The reactive power is decreased
In a 3Ø circuit, how many electrical degrees separate each phase: Right Ans
- 120
Ground fault protection for personnel on a 120 volt single-phase circuit is
based on? Right Ans - Unbalanced current between the grounded and
ungrounded conductor.
Voltmeter Right Ans - A high resistance is connected in series with the
internal coil of a galvanometer to make?
If a transformer ratio is 20/1, what does it mean for the secondary? Right
Ans - The primary voltage is 20 times greater than that of the secondary.
If a motor enclosure is designed to contain sparks or flashes that could ignite
surrounding vapors or gases, then the enclosure is considered to be which of
the following: Right Ans - Ventilated
The output of a 3-phase transformer is measured in what units? Right Ans -
Amperes
In order to change the rotation of a DC series motor, what must be done?
Right Ans - F1 and F2 must be reversed.
What does Bonding do? Right Ans - Controls the load on the system
installation
A meter used to measure both AC and DC voltage and current is known as?
Right Ans - Multimeter
What material is used on conduits inside and outside of a box? Right Ans -
Couplings
If a transformer has a voltage step-down from 117 volts to 6 volts then the
ratio of the transformer is equal to what? Right Ans - 1: 19, 5
If the power factor of a circuit is increased, then what occurs? Right Ans -
The reactive power is decreased
In a 3Ø circuit, how many electrical degrees separate each phase: Right Ans
- 120
Ground fault protection for personnel on a 120 volt single-phase circuit is
based on? Right Ans - Unbalanced current between the grounded and
ungrounded conductor.
