Deck 4: Ohms Law

Question 1

If the resistance in a circuit is kept the same, but the voltage is varied, the current will ______________.

Answer 1

vary

Question 2

Whenever there is current through a resistance, it must have a potential difference across its two ends equal to the ______________ product.

Answer 2

IR

Question 3

A ______________ is a material whose elements have an atomic structure that allows free electrons to drift through it with more or less force applied.

Answer 3

resistance

Question 4

One ______________ is the amount of current through a one-ohm resistance that has one volt of potential difference applied across it.

Question 5

Multiple and submultiple values used in electronic applications are based on the ______________ system of units.

Question 6

The Ohm's law formula states that V and I are ______________ proportional for any one value of R.

Question 7

When plotting a graph of current versus voltage, the horizontal axis is referred to as the x axis or as the ______________.

Question 8

Ohm's law states that current is ______________ proportional to resistance.

Question 9

What piece of equipment provides a variable dc output voltage to electronic circuits under test?

A) Signal generator
B) Multimeter
C) Power supply
D) Oscilloscope

Question 10

Some material whose elements have an atomic structure that allows free electrons to drift through it with more or less force applied is a

A) conductance
B) joule
C) short
D) resistance

Question 11

What is the potential difference across a one-ohm resistance that has one ampere of current through it?

A) One volt
B) One ampere
C) One watt
D) One joule

Question 12

The metric system uses what letter for 1 million?

A) G
B) T
C) m
D) M

Question 13

A graph that shows how much current a resistor allows for different voltages is called the

A) watt-hour characteristic of R
B) volt-ampere characteristic of R
C) volt-ohm characteristic of R
D) joule-ampere characteristic of R

Question 14

A straight-line graph shows that a resistor is

A) linear
B) nonlinear
C) very large
D) very small

Question 15

An example of a nonlinear resistance is the

A) carbon resistor
B) copper wire
C) tungsten filament
D) conductor silver

Question 16

When the applied voltage is constant, the current is more with

A) less resistance
B) more resistance
C) less conductance
D) an open circuit

Question 17

The work done in one second by one volt of potential difference in moving one coulomb of charge is the

A) joule
B) watt
C) ohm
D) watt-second

Question 18

Power is equal to

A) V x R
B) I x R
C) I x V
D) I / V

Question 19

The rate at which charge is forced to move by voltage is called

A) electric power
B) horsepower
C) watt-hours
D) joules

Question 20

What is the power in a circuit where the source of 100 V produces 2 A in a 50-? R?

A) 200 W
B) 20 W
C) 2 W
D) 2 KW

Question 21

How much current is needed for a 600-W, 120-V toaster?

A) 0.5 A
B) 5 mA
C) 5 A
D) 50 mA

Question 22

What is the resistor safety factor that allows the resistor to operate without breaking down from excessive heat?

A) 2
B) 3
C) 4
D) 5

Question 23

The maximum allowable voltage that a resistor can safely withstand without internal arcing is called the

A) maximum arcing voltage rating
B) maximum working voltage rating
C) maximum internal voltage rating
D) maximum power voltage rating

Question 24

A sudden involuntary contraction of the muscles, with a feeling of pain, caused by current through the body is referred to as

A) exercise
B) grounding
C) shock
D) work

Question 25

One of the best safety rules is to

A) work on circuits with power disconnected whenever possible
B) work while standing on earth ground
C) work with power connected whenever possible
D) work with both hands in your pockets

Question 26

When the current flow in a circuit becomes excessive, a resistor is more likely to

A) short
B) open
C) hum
D) get very cold

Question 27

Concerning electric shock, the threshold of sensation occurs when the current through the body is only slightly above _________ A.

A) 0.001
B) 0.01
C) 0.1
D) 1.0

Question 28

Ohm's law states that the amount of current is directly proportional to the voltage and inversely proportional to the resistance.

Question 29

The fact is that high-voltage circuits usually do have small values of current in electronic equipment.

Question 30

Whenever there is current through a resistance, it must have a potential difference across its two ends equal to the IR sum.

Question 31

A resistance can be considered some material whose elements have an atomic structure that allows free electrons to drift through it with more or less force applied.

Question 32

One ampere is the amount of current through a one-ohm resistance that has one volt of potential difference applied across it.

Question 33

A graph referred to as the volt-ampere characteristic of R shows how much resistance exists for different currents.

Question 34

A straight-line graph shows that a resistor is nonlinear.

Question 35

The unit of electric power is the joule.

Question 36

One horsepower (hp) is equal to three-quarter kilowatt.

Question 37

We pay for electricity in kilowatts.

Question 38

Power is generated by the source of applied voltage and consumed in the resistance as heat.

Question 39

Power is equal to voltage times current.

Question 40

The maximum working voltage of a resistor is the maximum allowable voltage that the resistor can safely withstand without internal arcing.

Question 41

An important safety tip to follow is to keep yourself insulated from earth ground when working on power-line circuits.

Question 42

Note that the resistor itself is very likely to develop a short circuit because of the nature of its construction.