Electricity And Energy

Question 1

Give 4 examples of electric fields in use

Answer 1

Laser printing
Paint spraying
Cling film
Dust removal

Question 2

Define electric current

Answer 2

Charge passing per unit time

Question 3

When dc charge moves around a circuit what direction does it move in only one direction?

Answer 3

Yes

Question 4

How does dc charge show on an oscilloscope?

Answer 4

Horizontal flat line

Question 5

Where does dc come from?

Answer 5

Batteries

Question 6

How do ac Charges move

Answer 6

Back and forth

Question 7

is an ac charge alternating?

Answer 7

Yes moves from negative to positive them back

Question 8

What shape does an ac current give on an oscilloscope?

Answer 8

A wave

Question 9

Where does ac come from?

Answer 9

Mains supply (50hz)

Question 10

What effect do resistors have on both current types? (Ac and dc)

Answer 10

None

Question 11

What do capacitors do to dc current?

Answer 11

Bring current to zero

Question 12

What do capacitors do to ac current?

Answer 12

Make ac current directly proportional to frequency

Question 13

What effect do lamps have on ac and dc currents?

Answer 13

No effect on either

Question 14

What will make lamps flash faster?

Answer 14

If ac frequency is increased

Question 15

What do diodes do to dc current

Answer 15

To pass in only one direction

Question 16

What do diodes do to ac current

Answer 16

Allow only half to pass

Question 17

Define work done

Answer 17

The amount of energy transferred by potential difference, voltage,

Question 18

Define potential difference

Answer 18

The work done per unit of charge

Question 19

Define resistance

Answer 19

The opposition to electric current

Question 20

What is an ammeter used to measure

Answer 20

The flow of charge

Question 21

Where must an ammeter be connected to?

Answer 21

A series circuit to measure current

Question 22

What is current measured in?

Answer 22

Amperes

Question 23

What’s a go.gmeter used for?

Answer 23

Measuring potential difference

Question 24

What is voltage measured in

Answer 24

Volts

Question 25

How do you measure the resistance of a component ?

Answer 25

With an ohmeter not connected to power

Question 26

What is resistance measured in ?

Answer 26

Ohms

Question 27

What's the effect of wire material on resistamce

Answer 27

Some metals have a greater resistance than others

Question 28

Whats the effect of wire thickness on resistamce

Answer 28

Thinner the wire the more resistance

Question 29

Effect of wire length on resistance?

Answer 29

Longer wire more resistamce

Question 30

What happens to the voltages in a series circuit?

Answer 30

Voltages across all components add up to make voltage supply

Question 31

In series what happens to resistance of each component

Answer 31

They add up

Question 32

Give an example of series circuit

Answer 32

Old fashioned Christmas tree lights

Question 33

What happens to current in parallel circuits

Answer 33

Current from supply splits up between all points

Question 34

What effect does changing resistamce have on electrical current

Answer 34

As resistance increases current decrease

Question 35

What effect does the change of resistance have on voltage

Answer 35

As resistamce increases so does voltage

Question 36

Define thermistor

Answer 36

Temperature dependent resistor

Question 37

What type of device is a thermistor

Answer 37

Input

Question 38

As the temperature of a thermistor increases what happens to its resistance

Answer 38

Resistance down. Turd

Question 39

Define an LDR

Answer 39

Light dependent resistor

Question 40

As LDR irradiance increases what happens to its resistance

Answer 40

Goes down. LURD

Question 41

Is an LDR an input or output device

Answer 41

Input

Question 42

What's the function of a solar cell

Answer 42

Converts light energy into electrical energy

Question 43

As irradiance on a solar cell increases what happens to its voltage

Answer 43

It increases

Question 44

Is a solar cell an input or output device

Answer 44

Input

Question 45

What's the function of a thermocouple

Answer 45

Converts heat energy into electrical energy

Question 46

Thermocouple am input or output device

Answer 46

Input

Question 47

What is a fuse

Answer 47

A safety device

Question 48

If an appliance is rated at less than 700w what type of fuse should be used

Answer 48

Three amp

Question 49

If an appliance is greater than 700w what type of fuse should be used

Answer 49

13a

Question 50

Define power

Answer 50

Energy transferred per unit time

Question 51

Can energy be destroyed

Answer 51

No but it can be changed

Question 52

Where does the Kelvin scale cut the axis?

Answer 52

-273 degrees

Question 53

How to work out kelvin

Answer 53

Celcius + 273

Question 54

What's it called when an force is used to move an object and energy is used

Answer 54

Work energy

Question 55

What is all energy measured in

Answer 55

Joules

Question 56

Define specific heat capacity

Answer 56

Number of joules of energy required to change the temperature of 1kg of materials by 1 degree

Question 57

Give the effect that similar or opposite charges have on each other

Answer 57

Similar repel | Opposites attract

Question 58

What is specific latent heat

Answer 58

Amount of heat energy required for a substance to change state

Question 59

What's it called when a substance changes state from solid to liquid

Answer 59

Fusion

Question 60

What's it called when a substance changes state from liquid to gas

Answer 60

Vaporization

Question 61

What happens to temperature when a substance changes state

Answer 61

Remains constant

Question 62

Define pressure

Answer 62

A force working at right angles to a surface

Question 63

What is 1 pascal equal to

Answer 63

I Newton per square meter

Question 64

What three things can change on a fixed mass of gas

Answer 64

Pressure Volume Temperature