[D2L] Final Review

Question 1

What is the term for electrical charge at rest?

Answer 1

Electrostatic

Question 2

What is required to form a magnetic domain (all atoms become aligned resulting in magnetism in one direction)?

Answer 2

Magnetic moments

Question 3

How many electrons in a coulomb

Answer 3

6.28 x 10 exponent 18

Question 4

one volt is the value of the difference in charge that will cause a current of one ampere to flow in a circuit with a resistance of one ohm

Answer 4

True

Question 5

What affects the ability of a conductor to transmit an electrical current?

a) Cross-sectional area
b) Length
c) Diameter
d) All of the above

Answer 5

All of the above

Question 6

What are the 4 components of a practical electrical circuit? (what is required for a proper circuit)

Answer 6

Source of emf, conductors, switch, load

Question 7

To calculate the Emax value of a sine wave, Divide the RMS value by the ( ) or Multiply RMS by ( ).

Answer 7

Sine of 45°, √2 (square root 2)

Question 8

Determine the instantaneous voltage at 30° if an ac voltmeter reads 110v

Answer 8

78v
(AC voltmeter = RMS)

Question 9

Which of the statements are true?

a) Voltage has the same charge between two points
b) Voltage is measured across a device, between two separate points along two different conductors
c) Voltage can be defined as a balance of electron distribution
d) Voltage is the measurement of difference in charge between 2 poles

Answer 9

Voltage is the measurement of difference in charge between 2 poles

Question 10

An (emf) electromotive force maintains the difference in charge

Answer 10

True

Question 11

What is the symbol for electrical Charge?

Answer 11

Q

Question 12

There are six methods for producing an emf. Pick 2 source names that ARE NOT methods. (MULTISELECT)

a) Light
b) Heat
c) Electrical
d) Pressure
e) Radiant
f) Chemical

Answer 12

Electrical
Radiant

Question 13

Using a “CAT-l” electrical meter device, you can test utility connections and power lines?

Answer 13

False, CAT 3 & 4

Question 14

Which one is incorrect?

a) Never use an ohmmeter on a energized circuit.

b) Clamp around only one wire when using an ammeter

c) If the display meter is flashing on and off, the measurement is greater than the range overload setting on the meter

d) When checking polarity on an AC circuit, Red goes to hot, Black goes to Negative

Answer 14

When checking polarity on an AC circuit, Red goes to hot, Black goes to Negative

Question 15

In an Capacitive circuit, Current leads Voltage by 90 degrees?

Answer 15

True (ICE)

Question 16

????If the instantaneous voltage is 10V at 110 degrees, what would voltmeter read?

Answer 16

7.937

Question 17

A lock that you use to lock out equipment can have more then one key?

Answer 17

False, only one

Question 18

what amount of electrical current can cause heart failure or death?

Answer 18

100mA to 200mA

Question 19

A Transformer is a…..

Answer 19

Series of windings used to step up/down voltage

Question 20

Inductance is the opposition of

Answer 20

Change in Current

Question 21

what is the positive plate called on a battery? (hint: the negative plate has an “n” in the word”)

Answer 21

Cathode (Positive)

Anode (Negative)

Question 22

Thermocouples use heat to generate Electricity?

Answer 22

True

Question 23

What is Faraday’s law?

Answer 23

States that the magnitude of an induced voltage of a conductor is proportional to the rate that it cuts the lines of flux from a magnet.

Question 24

A conductor moving parallel to lines of magnetic forces produce:

Answer 24

Minimum emf

Question 25

what does increasing the current in a coil do to the EMF

Answer 25

increase the EMF

Question 26

the number of turns on the primary and secondary coils determines the amount of the mutually induced secondary coil voltage.

Answer 26

True

Question 27

Gas burners can have built-in _______ ignition system. (think BBQ)

Answer 27

piezo-based

Question 28

What is the order of the 7 steps normally used in a lockout procedure? (Drop down selection)

Answer 28

1. Notification 2. Shutdown 3. System Shutdown 4. Lockout 5. Tag 6. Recheck 7. Re-energize

Question 29

What are the steps for preforming an operational test of an ohm meter before you check for a voltage in an unknown circuit? (Multi select) a) Check meter to a known voltage b) Check the circuit c) If it shows de-energized, check meter to a known voltage source again d) Check polarity of circuit e) Make sure the power source is on and stable

Answer 29

a) Check meter to a known voltage b) Check the circuit c) If it shows de-energized, check meter to a known voltage source again

Question 30

If the amperage reading is lower then your clamp-on ammeter's capability, you can loop the single conductor through the clamp to take a reading.

Answer 30

True

Question 31

Polarity is NOT a factor when using an ohmmeter.

Answer 31

True

Question 32

Polarity is NOT important when measuring ac currents.

Answer 32

True

Question 33

which of the following factors determine the extent of injury a current will have on the body? (Multi select, pick 4) a) A persons skin resistance b) Improper grounding c) Size of the area of contact d) Which part of the body is in contact e) puddles on the ground f) how much pressure is applied

Answer 33

a) A persons skin resistance c) Size of the area of contact d) Which part of the body is in contact f) how much pressure is applied

Question 34

what is the voltage rating for Class 0 (red) electrical rubber gloves?

Answer 34

up to 1,000 V

Question 35

One alternation occurs within 180 degrees of an electrical sine wave

Answer 35

True, 360 is a cycle

Question 36

The time required for one alternation to complete is also known as a period.

Answer 36

False

Question 37

One cycle is one positive alternation and one negative alternation

Answer 37

True

Question 38

When a 4 pole alternator turns 1500r/min the output frequency is 60hz

Answer 38

False, it's 50Hz

Question 39

Three phase wires are White, Black, and Blue? T or F

Answer 39

False Phase A: black Phase B: red Phase C: blue

Question 40

Fuse rating can not be greater than 125% of the smallest wire or component in the circuit

Answer 40

True

Question 41

Single conductors may have a max load of 80% of the rated 15A

Answer 41

True

Question 42

Arc flash can be caused by environmental, aging material and worker interaction. Which of these is not a likely concern a) Condensation b) Dust on circuits c) Resetting a circuit breaker d) Current in mA

Answer 42

Current in mA

Question 43

Fuses allow 3x their rated current for a few seconds for surging of motors

Answer 43

True

Question 44

What is flux density?

Answer 44

The number of lines of force passing through a unit area of material

Question 45

What are some examples of Ferromagnetic materials? (MULTI-SELECT) Iron Wood Nickel Cobalt Glass

Answer 45

Iron Nickel Glass

Question 46

What pole do flux lines leave and then enter?

Answer 46

Leave through the north and enter through the south

Question 47

What is a Megohmmeter (Meggar) used for?

Answer 47

Checking Wire Insulation

Question 48

If a wire is shorted out If a wire is burnt open

Answer 48

Just think of it as an open switch(not there) not functionable, no current can flow

Question 49

GFCI(Ground Fault Circuit Interrupter) detects leakage as low as 3-5mA (0.003-0.005A)

Answer 49

True