Unit 8 Science

Question 1

What is the SI unit for potential difference?

Answer 1

volts (V)

Question 2

Similar charges tend to ____________ one another.

Answer 2

repel

Question 3

What happens to an atom that loses electrons?

Answer 3

It becomes positively charged.

Question 4

What tends to resist the flow of electric charges?

Answer 4

insulator

Question 5

What is the SI unit for current?

Answer 5

ampere (A)

Question 6

What are the two types of current?

Answer 6

Alternating and Direct

Question 7

What is the symbol for electric current?

Answer 7

I

Question 8

Opposite charges tend to ____________ one another.

Answer 8

attract

Question 9

What is the rate that electric charges move through a wire in a single direction?

Answer 9

electric current

Question 10

What happens to an atom that gains electrons?

Answer 10

It becomes negatively charged.

Question 11

A resistor has a resistance of 120 Ω. How much current is in the resistor if there is a potential difference of 12.0 V across the resistor? [I=V/R]

Answer 11

0.10 A

Question 12

A set of electric trains are powered by a 9 V battery. What is the resistance of the trains if they draw 4.0 A of current? [I=V/R]

Answer 12

2.3 Ω

Question 13

A 13 Ω resistor has 0.050 A of current in it. What is the potential difference across the resistor? [I=V/R]

Answer 13

0.65 V

Question 14

The SI unit of resistance is the

Answer 14

ohm

Question 15

Objects become charged when _________ are moved from one object to another.

Answer 15

electrons

Question 16

Positively charged objects have _____ positive than negative charges.

Answer 16

more

Question 17

Negatively charged objects have _____ positive than negative charges.

Answer 17

less

Question 18

Neutral objects have ______ positive than negative charges.

Answer 18

equal

Question 19

A substance that resists the flow of electrons or electrical charge.

Answer 19

insulator

Question 20

A substance that allows electrons (or electric charge) to easily flow through it.

Answer 20

conductor

Question 21

Ohm’s Law Formula

Answer 21

I = V/R
Current = Voltage/Resistance

Question 22

In an electrical field, the resistance is 2 Ω and the current is 4 A. What is the voltage?

Answer 22

I = V/R
Current = Voltage/Resistance
Voltage = 8 V

Question 23

A refrigerator receives 240 V of electricity. If it uses 32 A of current, what is the resistance of the refrigerator?

Answer 23

I = V/R
Current = Voltage/Resistance
Resistance = 7.5 Ω

Question 24

What is the voltage across a 75 Ω resistor with 1.5 A of current?

Answer 24

I = V/R
Current = Voltage/Resistance
Voltage = 112.5 V

Question 25

In a simple series circuit, why does the bulb light up when you close the switch?

Answer 25

The bulb lights up when the switch is closed because it creates a closed path for electrons to flow through.

Question 26

In a simple series circuit, why does the bulb go out when you open the switch?

Answer 26

The bulb stops lighting up with an opened switch, as there is no longer a path of electron flow.

Question 27

Define electric circuit.

Answer 27

An electric circuit is a path that electrons flow through.

Question 28

What happens to the electric current in a series circuit when voltage decreases?

Answer 28

electric current decreases

Question 29

What happens to the electric current in a series circuit when voltage increases?

Answer 29

electric current increases

Question 30

What happens to the electric current in a series circuit when resistance increases?

Answer 30

electric current decreases

Question 31

What happens to the electric current in a series circuit when resistance decreases?

Answer 31

electric current increases

Question 32

Describe a parallel circuit.

Answer 32

A parallel circuit contains two or more paths for current to flow through.

Question 33

In a parallel circuit containing 3 light bulbs, what happens to the other two bulbs when one goes out?

Answer 33

The other two bulbs will not go out.

Question 34

In a parallel circuit, the total current is equal to _____________

Answer 34

the sum of the current in each path.

Question 35

In a parallel circuit, voltage is (same/different) across each component.

Answer 35

same

Question 36

The total resistance is (less/more) than the resistance of one resistor alone.

Answer 36

less

Question 37

The bulbs in a (parallel/series) circuit are brighter than bulbs in a (parallel/series) circuit.

Answer 37

parallel, series

Question 38

The battery life is typically shorter in a (parallel/series) circuit when compared to (parallel/series) circuits.

Answer 38

parallel, series