Chapter3

Question 1

Fuses for overload protection, may be used in what type of circuit?

Answer 1

Answer : 3 wire, 3 phase, 1 conductor grounded

Question 2

What is the circular mil (cmil) area for a stranded conductor with a diameter of 0.260 inches?

Answer 2

Answer : 52,620 cmil
(1 cmil = cir area of .001 inch dia.)

See Chapter 9, Table 8.

Question 3

What makes electrons move in a conductor?

Answer 3

Answer : EMF, voltage, potential.

Question 4

The “Left Hand Rule” is commonly used to determine?

Answer 4

Answer : Used to indicate the path of electrical current and the direction of a circuit’s magnetic north.

Question 5

Electrical current in a conductor, creates what around the conductor?

Answer 5

Answer : Creates a magnetic flux field around the conductor.

Question 6

Three resistors and connected in series. How is the total resistance calculated?

Answer 6

Answer : The resistor values are added together.

Question 7

In the circuit above, how is the circuit’s total current (amperes) calculated?

Answer 7

Answer :
I = E (volts) ÷ R (circuit resistance)
I = 120V ÷ 80 Ω = 1.5A

Question 8

A solid wire has a diameter of ~ 0.102 inches. The wire has a circular area of approximately how many cmils?

Answer 8

Answer : Chapter 9, Table 8 10380 cmils

Question 9

“Voltage drop” is equal to what formula (from the EIR circle)

Answer 9

Answer : E (voltage drop) = I (current) x R (resistance)

Question 10

1200 mA is equal to how many amperes?

Answer 10

Answer : 1.2 A

Question 11

120 ac volts, is equal to how many peak ac volts?

Answer 11

Answer : 170 (peak volts)

(RMS) x 1.414 = peak volts

Question 12

A non grounding receptacle is replaced with grounding receptacle. What must be done to comply with the MRC?

Answer 12

Answer :
Option: 1 The replaced receptacle must be labeled “no equipment ground”

Option: 2 If supplied thru a GFCI, the replaced receptacle must be labeled “GFCI protected” and “no equipment ground”

MRC E4002.15