84-85 - Static and Current and P.D

Question 1

Why does static electricity only occur in insulators?

Answer 1

The charges are not free to move so they build up in one place

Question 2

How does friction cause static?

Answer 2

Negative ions from one surface are attracted to the positive charge on the other surface

Question 3

How is a positive charge formed on one surface?

Answer 3

The electrons are repelled when the other material comes too close

Question 4

Which charge can move?

Answer 4

Negative electrons only

Question 5

What happens between two like charges?

Answer 5

They repel

Question 6

What makes a material a good conductor?

Answer 6

Electrical charges move easily through them

Question 7

What is the definition of current?

Answer 7

Rate of flow of electric charge

Question 8

What is the unit for current?

Answer 8

Ampere (A)

Question 9

What is the condition for current flowing through a component?

Answer 9

Current only flows if there is potential difference across a component

Question 10

What is the definition of potential difference?

Answer 10

Driving force that pushes the current

Question 11

What are the units for potential difference?

Answer 11

Volts (V)

Question 12

What is the definition of resistance?

Answer 12

Something which slows down the flow

Question 13

What is the unit for resistance?

Answer 13

Ohm (Ω)

Question 14

The greater the resistance, the _____ the current

Answer 14

Smaller

Question 15

What is charge measured in?

Answer 15

Coulombs

Question 16

Charge/Time =

Answer 16

Current

Question 17

Time * Current =

Answer 17

Charge

Question 18

What does a large current do to the charge?

Answer 18

Increases the charge

Question 19

How do you find potential difference?

Answer 19

PD = work done/charge passing between two points

Question 20

What is potential difference a measurement of?

Answer 20

Amount of energy transferred by an electrical component per unit of charge