Studied by 10 people

5.0(1)

Get a hint

Hint

1

What is electricity?

A flow of electrons along a wire

New cards

2

What happens when electrons move along the wire?

As the electrons move along the wire, they collide with the metal atoms. These collisions make the atoms vibrate more, which makes the metal hotter

New cards

3

What is resistance a measure of?

Resistance is a measure of how much a material tries to stop electricity from passing through it

New cards

4

Why do appliances waste energy?

All wires and devices have some resistance, which is why electrical appliances always waste some energy as heat

New cards

5

What is a resistor?

A component designed to reduce the current

New cards

6

What is a variable resistor?

It has a resistance that can be changed

New cards

7

What is a fixed resistor?

It has a resistance that remains the same

New cards

8

What affects resistance?

Material

Thickness

Temperature

Length

New cards

9

How does material affect resistance?

Some materials allow electricity to flow through easier, such as copper

New cards

10

How does thickness affect resistance?

Increasing thickness decreases resistance

New cards

11

How does temperature affect resistance?

Decreasing temperature decreases resistance

New cards

12

How does length affect resistance?

Increasing length increases resistance

New cards

13

What is a superconductor?

A material that conducts electricity with a very low resistance at very low temperatures

New cards

14

What does Ohm’s law relate?

It relates current, voltage, and resistance in a three way relationship

New cards

15

When voltage in a circuit is increased, does the current increase or decrease?

Voltage is directly proportional to current. When voltage in a circuit is increased, the current also increases (as long as resistance is constant)

New cards

16

What is the symbol for current?

I

New cards

17

When resistance decreases in a circuit, does current increase or decrease?

Resistance is inversely proportional to current. When resistance decreases in a circuit, current increases (as long as voltage is constant)

New cards

18

What is Ohm’s law?

V = IR (Voltage equals current times resistance)

New cards

19

What is the unit for resistance?

Ohm (the symbol is Ω)

New cards

20

How are ohm’s measured?

Using an ohmmeter

New cards

21

What is the symbol for current?

I

New cards

22

What is the unit for current?

Amps

New cards

23

What is the symbol for voltage?

V

New cards

24

What is the unit for voltage?

Volts

New cards

25

What is the symbol for resistance?

Ω

New cards

26

What is the unit for resistance?

Ohm’s

New cards

27

What happens if you get kiloamps or milliamps or kilovolts of millivolts or milloohms or milliohms?

Kilo or milli before a unit (A, V, or Ω) is not allowed. You have to convert it to a normal unit. If it has kilo, you times it by 1000. If it has milli, you multiply by 1000

New cards