2.4 Current Electricity

Question 1

How is static electricity created?

Answer 1

When two electrically insulating materials are rubbed together electrons are rubbed off one material and deposited on the other

Question 2

What happens to the material that gains electrons in static electricity?

Answer 2

It becomes negatively charged

Question 3

What happens to the material that loses electrons in static electricity?

Answer 3

It becomes positively charged

Question 4

What is the process of creating static electricity called?

Answer 4

Charging by friction

Question 5

When two electrically charged objects are brought together what happens?

Answer 5

They exert a force on each other

Question 6

What do two object with the same charge do?

Answer 6

Repel each other

Question 7

What do two objects with opposite charges do?

Answer 7

They attract each other

Question 8

The bigger the distance between electrically charge objects…

Answer 8

The weaker the force between them

Question 9

What does a resistor do?

Answer 9

Reduces current flow

Question 10

What does a variable resistor do?

Answer 10

Alter the amount of current continuously depending on the conditions

Question 11

What does a thermistor do?

Answer 11

Changes the current flow as temperature changes

Question 12

Does a voltmeter go in in series or parallel?

Answer 12

Parallel

Question 13

Does a ammeter go in in series or parallel?

Answer 13

Series

Question 14

What does a light dependent resistor do?

Answer 14

Changes the current depending on the light

Question 15

What does a diode do?

Answer 15

Allows current to only flow in one direction

Question 16

What is current?

Answer 16

It is the rate of flow of electrical charge through a current

Question 17

What is the unit of flow of charge?

Answer 17

Coulombs

Question 18

What is potential difference?

Answer 18

Voltage

The work done for every coulomb of charge flowing through the circuit

Which means the energy carried per electron

Question 19

Current in a series circuit?

Answer 19

Same

Question 20

Current in a parallel circuit?

Answer 20

Splits

Question 21

Voltage in a parallel circuit?

Answer 21

Same

Question 22

Voltage in a series circuit?

Answer 22

Splits

Question 23

What is resistance?

Answer 23

The opposition to current flow

Question 24

What is resistance measured in?

Answer 24

Ohms

Question 25

What is ohms law shown on a graph?

Answer 25

``` If a resistor is kept at a constant temperature the current-voltage graph is... Directly proportional Passes through (0,0) As voltage doubles current doubles ```

Question 26

What is ohms law in summary?

Answer 26

The current through a wire is proportional to the voltage across it provided the temperature remains constant

Question 27

What is a component called that obeys ohms law?

Answer 27

An ohmic conductor

Question 28

How do you work out the total resistance in a series circuit?

Answer 28

R1+R2+R3.... etc | Just add them

Question 29

How do you work out the total resistance in a parallel circuit?

Answer 29

1/TR = 1/R1 + 1/R2 + 1/R3 ... etc

Question 30

What happens to the resistance in a filament bulb as a result of temperature?

Answer 30

Resistance increases as the temperature increases

Question 31

Why does the temperature increase in a bulb with more current/voltage

Answer 31

The more energy there is for friction giving off heat

Question 32

Because a diode only flows in one direction what is the resistance like in the other direction?

Answer 32

Very high

Question 33

What does a diode need before current is produced?

Answer 33

A certain amount of voltage is needed before a current is produced On a graph the line doesn't start at the origin But as voltage increases so does current

Question 34

In a thermistor what will low temperature do to the resistance?

Answer 34

High resistance

Question 35

In a thermistor what will a high temperature do to the resistance?

Answer 35

Low resistance

Question 36

How does resistance link to light in an LDR?

Answer 36

Resistance decreases as light intensity increases