P2.3

Question 1

What does static mean?

Answer 1

Still

Question 2

What happens if a plastic is rubbed by a dry cloth?

Answer 2

~ The rod and cloth can become electrically charged
~ The plastic has an equal number of protons and electrons, as does the cloth
~ When rubbed some electrons from one can be transferred to the other which imbalances the charge on both of them

Question 3

What do opposite charges do?

Answer 3

Attract

Question 4

What do like charges do?

Answer 4

Repel

Question 5

What are some examples of static electricity?

Answer 5

~ Balloons being rubbed on something and sticking to a wall
~ Van der graaf generator
~ Trampoline carpets

Question 6

What charge does a gain of electrons give?

Answer 6

Negative charge

Question 7

What charge does a loss of electrons give?

Answer 7

Positive charge

Question 8

What does a voltmeter measure?

Answer 8

Voltage / potential difference

Question 9

What does an ammeter measure?

Answer 9

Current (amps)

Question 10

What does a fixed resistor do?

Answer 10

Lower the current, measured in ohms

Question 11

What is a thermistor?

Answer 11

A heat sensor, used in thermostats

Question 12

What are light dependent resistors used for?

Answer 12

Switching on circuits depending on whether there is light (like streetlights)

Question 13

What can light emitting diodes be used for?

Answer 13

Making efficient lighting which only uses a little electricity but produces lots of light

Question 14

What is electric current?

Answer 14

The flow of charge, measured with an ammeter

Question 15

What is the measure of the large amount of electrons in an electric current?

Answer 15

1 coulomb

Question 16

What is current a measure of?

Answer 16

The flow of coulombs per second

Question 17

What does the letter I stand for?

Answer 17

Current (amps)

Question 18

What does the letter Q stand for?

Answer 18

Charge (coulombs)

Question 19

What is another word for potential difference?

Answer 19

Voltage

Question 20

What is potential difference?

Answer 20

Energy transferred per coulomb of charge

Question 21

What does work done mean?

Answer 21

Energy transferred

Question 22

What is the units of potential difference?

Answer 22

Volts

Question 23

What is work done/energy transferred measured in?

Answer 23

Joules

Question 24

As the current increases what else increases?

Answer 24

Potential difference

Question 25

Current is directly proportional to what?

Answer 25

The potential difference

Question 26

In series circuits, the total resistance is the sum of...

Answer 26

All the individual resistors or components

Question 27

In series circuits, the total potential difference of the cells is the sum of...

Answer 27

The individual cells

Question 28

In a series circuit the potential difference is shared between...

Answer 28

The components

Question 29

In series circuits, the current is...

Answer 29

The same throughout and through each component

Question 30

In parallel circuits, the potential difference across each component is...

Answer 30

The same

Question 31

In parallel circuits, the current is different...

Answer 31

In different branches of the circuit

Question 32

In parallel circuits, the total current through the whole circuit is the sum of...

Answer 32

The current through the separate components

Question 33

The higher the resistance...

Answer 33

The lower the current

Question 34

The higher the temperature...

Answer 34

The lower the resistance, so more current can flow

Question 35

A diode makes the current flow...

Answer 35

In only one direction

Question 36

Why does the current decrease when a conductor is heated?

Answer 36

~ Heat causes the free atoms/ions to vibrate more | ~ Electrons collide more frequently which reduces the current

Question 37

What do electrically charged objects do when they're brought together?

Answer 37

Exert a force on each other

Question 38

What is current a flow of?

Answer 38

Charge

Question 39

How can the resistance of a component be found?

Answer 39

By measuring the current through the components and the potential difference across the components

Question 40

What is the measure of resistance?

Answer 40

Ohms

Question 41

Why is the an increasing use of LEDs for lighting?

Answer 41

They use a much smaller current than other forms of lighting

Question 42

As the resistance of a light dependent resistor decreases...

Answer 42

The light intensity increases

Question 43

As the temperature of a thermistor decreases...

Answer 43

The temperature increases

Question 44

What are uses of LDRs?

Answer 44

~ Automatic lights ~ Camera shutter ~ Fridge lights

Question 45

What are uses of thermistors?

Answer 45

Heating systems

Question 46

What are uses of LEDs?

Answer 46

Efficient lamps