Watts & Electrical Power

Question 1

What are the three most basic units in electricity?

Answer 1

voltage (V), Current (I) and resistance (r)

Question 2

How is voltage measured?

Answer 2

in volts

Question 3

How is current measured?

Answer 3

in amps

Question 4

how is resistance measured?

Answer 4

in ohms

Question 5

resistance produces what?

Answer 5

light, heat or both

Question 6

How is electrical powered measured?

Answer 6

in watts

Question 7

A measure of amount of electrical “stimulus” needed to enable current to flow through a circuit is?

Answer 7

Volts

Question 8

a majority of line-voltage lighting applications operate at?

Answer 8

120 volts

Question 9

Some large scale commerical lighting applications operate at?

Answer 9

277 volts

Question 10

low-voltage lighting applications usually operate at?

Answer 10

12 volts

Question 11

A measure of quantity of electrical particle flow in a circuit

Answer 11

Amps

Question 12

circuits having higher currents require?

Answer 12

larger wire sizes. circuit breakers and switches

Question 13

what are lighting circuits rated at?

Answer 13

15-20 amps

Question 14

measure of electrical circuits ability to do work

Answer 14

watts

Question 15

what does an electrical circuit consist of?

Answer 15

voltage sourcce
resisstance or loads connected in a continuous loop
electrical conductors such as wires
control devices such as switches and safety devices designed to prevent electrical overloads such as circuit breakers

Question 16

the U.S has how many voltages for buildings?

Answer 16

4

Question 17

120/240-v single phase, 3 wire is primarily used where?

Answer 17

primary residential

Question 18

120/280-V three phase, 4 wire is primarily used where?

Answer 18

commerical

Question 19

277/480-V three phase, 4 wire is primarily used where?

Answer 19

commerical

Question 20

2400/4160-v is primarily used where?

Answer 20

very large buildings

Question 21

What is the equation to calculate watts-per-square-foot?

Answer 21

Watts per square foot=total watts / square footage

Question 22

what is the lighting power factor equation?

Answer 22

total # of watts consumed/ total area of space being lit