Electricity exam #1

Question 1

True or False

Using the AWG, 14G wire has a greater diameter than a 10G wire

Answer 1

False

Question 2

• Which of the following is not a resistor?
  a. an 11.5 KΩ resistor
  b. a 200 watt light bulb
  c. a 75 horsepower electric motor
  d. a large magnetic coil
  e. four 50 watt speakers

Answer 2

c. a 75 horsepower electric motor

Question 3

In a parallel circuit with 50 branches that has a cource voltage of 100 volts, what would be the vooltage if you measured it across each branch?

a. 2 volts
b. 10 volts
c. 50 volts
d. 100 volts
e. there is not enough information given to determin the answer

Answer 3

d. 100 volts

Question 4

ferromagnetic

Answer 4

easily magnetized

Question 5

Paramagnetic

Answer 5

semi- or quasi magnetic

Question 6

Diamagnetic

Answer 6

opposes magnetization

Question 7

If voltage = 10V and resistance 5000Ω, what is current?

Answer 7

0.002amps

Question 8

• If the source current is 6A, and the load voltage is 120V, what is the load current if the winding ratio is 10:1?
  a. 1.2 amps
  b. 0.6 amps
  c. 6 amps
  d. 60 amps
  e. 120 amps

Answer 8

d. 60 amps

source V is 120 x 10=1200V
A1 V1 = A2 V2
6A x 1200V = Aa x 100V
6A x 1200V
---------------   = 60A
120V

Question 9

• If the source voltage is 100 Volts and the load current is 2500 amps, what is the power if the winding ratio is 10:1?
  a. 250 watts
  b. 250 kilowatts
  c. 25 kilowatts
  d. 2.5 kilowatts
  e. 2,500,000 watts

Answer 9

c. 25 kilowatts

Load V

10V x 2500A = 25000

Question 10

The lines of magnetic flux around a wire with current flowing though it

a. are oriented with the direction of the wire
b. are oriented circumferentially to the wire
c. create a figure 8 pattern around the wire
d. get weaker toward the positive side of the wire
e. get weaker toward the negative side of the wire

Answer 10

b. are oriented circumferentially to the wire

Question 11

• In a parallel circuit, resistance
  a. is additive
  b. is the inverse of the sum of the inverses
  c. is the same everywhere in the parallel circuit
  d. is proportional to the voltage

Answer 11

b. is the inverse of the sum of the inverses

Question 12

The electrolyte in a battery

a. contains ions
b. provides the resistance
c. is electrically neutral
d. is rigid at room temp
e. makes good wine coolers

Answer 12

a. contains ions

Question 13

A series circuit has R1=800Ω, R2=5.6kΩ, and R3=7.5kΩ. 20 volts are supplied. What is the voltage drop across R2?

a. 14v
b. 0.14v
c. 19.7v
d. 8.1v
e. 10.8v

Answer 13

d. 8.1V

Question 14

Current in a series circuit is

Answer 14

the same everywhere

Question 15

Current in a parallel circuit is

Answer 15

divided among resistances

Question 16

True or False

The poles of a magnet are referred to as positive and negative, and opposite poles attract

Answer 16

True

Question 17

*True or false

The force field around a magnet is called charge

Answer 17

False

a force field around a magnet is called flux!

Question 18

True or false

As current flows through a wire, it creates an electromagnetic field.

Answer 18

True

Question 19

*True or False

in a magnet, the electrons spin in the same direction

Answer 19

True

Question 20

If V=10 volts and current is 5 amps, what is the power?

Answer 20

50 watts

Question 21

Which voltage type is capable of inducing an electromagnetic current through a transformer?

Answer 21

AC

Question 22

• if the source voltage is 120Vand the winding ratio is 10:1, what is the load voltage?
  a. 120 volts
  b. 12 volts
  c. 1200 volts
  d. 10 volts
  e. 1.0 volts

Answer 22

b. 12 volts

1/10 of source

Question 23

Power is determined by

Answer 23

A x V

Question 24

Primary winding (lots of winds) secondary winding (3 winds)

would this be a step up or step down transformer?

Answer 24

Step down

Question 25

magnet of charge

Answer 25

amps

Question 26

charge

Answer 26

coulombs

Question 27

force

Answer 27

volts

Question 28

resistance

Answer 28

ohms

Question 29

power

Answer 29

watts

Question 30

regarding resistors, which of the following is false?

a. resistors limit the flow of current in a circuit
b. resistance is the load of a circuit
c. resistance is labeled using the greek symbol omega Ω
d. resistance equals voltage times current
e. resistors contain a material in the core that determines resistance

Answer 30

d. resistance equals voltage times current

Question 31

If you have a circuit with R1=100Ω, R2=200Ω, and R3=300Ω in series. 12 volts are supplied by the power source. what is the voltage drop created by R2

Answer 31

4 volts

Question 32

• The term Hertz (Hz) can be stated as:
  a. seconds per cycle
  b. pulse repetition
  c. the period
  d. cycles per second
  e. time ( in seconds )

Answer 32

d. cycles per second

Question 33

True or False
Direct current is simpler to produce than AC current. It is a steady-state phenomenon as opposed to alternating current, whch changes polarity.

Answer 33

True

Question 34

True or false

we cells, like car batteries, are called wet because they contain ions in a solution within a non-reactive casing

Answer 34

True

Question 35

current

Answer 35

the quantity of elections flowing past a given point

Question 36

voltage

Answer 36

the elcetrical pressure or push

Question 37

power

Answer 37

the work performed by current

Question 38

resistance

Answer 38

the opposition to current flow

Question 39

Complete this statement

Current in a power source must flow from an area of _________ potential.

Answer 39

higher to lower

Question 40

*electrons typically cannot ______.

Answer 40

move through insulators

because the electrons in the outer cell dont like to move

Question 41

• electrons can be persuaded to move in a wire by any of the following except
  b. a complete circuit
  c. adding heat
  d. positive/negative equilibrium
  e. magnetism

Answer 41

d. positive/negative equalibrium

Question 42

*As the length of a wire (or blood vessel) increases, you would expect resistance to the flow of current to:

Answer 42

Increase