Deck 12: Basic Electricity and Magnetism

Question 1

When calculating the total resistance of a parallel circuit, the result will always be lower than the lowest resistance.

Answer 1

True

Question 2

What type of charge does an electron have?

A) Positive.
B) Negative.
C) Neutral.
D) Negative-positive.

Answer 2

B

Question 3

Typical insulators are: ____.

A) copper, silver, gold
B) steel, bronze, brass
C) glass, rubber, plastic
D) aluminum, nickel, magnesium

Answer 3

C

Question 4

If three bulbs are wired in parallel and one bulb burns out, the total current of the circuit will decrease.

Question 5

If a conductor carrying electrical current is formed into a coil, the magnetic field around the wire will ____.

A) cancel out
B) increase
C) decrease
D) remain the same

Question 6

As the diameter of a wire increases, its resistance will also increase.

Question 7

If five electrons combine with three protons, the net charge will be ____.

A) negative
B) positive
C) zero
D) neutral

Question 8

To find the watts of electrical power in an electrical circuit, you multiply ____  together .

A) ohms and amperes
B) ohms and volts
C) volts and amperes
D) volts, amperes, and ohms

Question 9

The unit of measurement for the charge a capacitor can store is called a Joule.

Question 10

What part of an atom moves from one atom to another?

A) Proton.
B) Neutron.
C) Electron.
D) Molecule.

Question 11

An element in an electric heating unit is connected to a 232-V power supply. The current flow through the element is 19 A. What is the resistance of the element ?

A) 8 Ω
B) 10 Ω
C) 12 Ω
D) 14 Ω

Question 12

Ohmmeters are to be used only on circuits that are de-energized.

Question 13

If two light bulbs are wired in series and one bulb burns out, the other bulb will ____.

A) go out
B) stay on
C) stay on, but it will be dimmer
D) stay on, but it will be brighter

Question 14

As loads are added in a parallel circuit, the total resistance of the circuit ____.

A) will increase
B) will decrease
C) will remain the same
D) cannot be determined

Question 15

What happens to the current in a circuit if the resistance is increased?

A) The current remains the same.
B) The current increases.
C) The current decreases.
D) This cannot be determined.

Question 16

The ampere is ____.

A) the difference in potential between two charges
B) a measure of the quantity of electrons flowing past a point in the electrical circuit in a given time
C) the unit of measure for resistance
D) the unit of measure for capacitance

Question 17

In a circuit with two or more resistances in parallel, the total resistance in the circuit is the sum of the resistances in the circuit.

Question 18

One kilowatt of electrical energy is equal to 1,000,000 watts.

Question 19

If a conductor carrying electrical current is formed into a coil, the strength of the magnetic field generated by the wire will increase.

Question 20

In a circuit with two or more resistances in series, the total resistance in the circuit is the sum of the resistances.

Question 21

If there was a current flow of 6 A in a 120-V circuit, the resistance of the circuit would be ____________________ Ω .

Question 22

The unit of measure for resistance is the ____________________.

Question 23

____________________ are used to measure the intensity of current flow in a circuit or a particular branch in a circuit, so they are wired in series with the circuit being evaluated.

Question 24

Three electric heating elements are connected in parallel with each other and each element draws 7 A. The supply voltage is 210 V .
a) What is the resistance of each heater?
b) What would the current be through each of the two remaining heaters if one heater burns out?

Question 25

A PTC thermistor causes the resistance of the thermistor to increase when its temperature rises.

Question 26

A good conductor of electricity has  few ____________________ electrons which can move easily from one atom to another.

Question 27

A heat sink is a device to improve the purity of the electrons in an electrical circuit.

Question 28

What is the difference between AC and DC current?

Question 29

A transformer has 10,000 turns of wire in the secondary and 100 turns in the primary. The transformer is connected to a line voltage of 120 V. The output voltage will be ____________________ volts.

Question 30

The main purpose of a rectifier is to convert direct current (DC) to alternating current (AC).

Question 31

A single diode can be connected as a full wave rectifier.

Question 32

Copper wire sizes are measured in circular mils.

Question 33

The unit of measure for the current flow of electrical energy is the ____________________.

Question 34

The unit of measure for the electrical pressure forcing electrical energy through a conductor is the ____________________.

Question 35

What is the total current in a circuit that has two electric heating elements that have resistances of 5 Ω and 20 Ω? The elements are connected in parallel with each other and are connected to a 200-V power supply .

Question 36

Write the three forms of Ohm's Law.

Question 37

A solid state device that allows electrical energy to flow through in only one direction is called a(n) ____________________.

Question 38

If ten 60-W light bulbs are wired in parallel with each other and are connected to a 120-V power supply, what will a voltmeter read if connected across any one bulb ?

Question 39

Why is rubber a good insulator?

Question 40

When checking a diode with an ohmmeter and the meter shows a resistance, if the meter leads are reversed, it should show infinity .

Question 41

What is meant by 60 hertz AC current?

Question 42

What are the three types of opposition to current flow that impedance represents?

Question 43

Describe a thermistor.

Question 44

If two electrical loads are connected in parallel with each other and each load draws 6 A, what is the total current of the circuit ?

Question 45

Describe inductance.

Question 46

How can a magnetic field around an iron core be generated ?