Electricity (4)

Question 1

What is matter made from?

Answer 1

Atoms.

Question 2

What happens to an atom when it loses electrons?

Answer 2

It becomes positively charged.

Question 3

What happens to an atom when it gains electrons?

Answer 3

It becomes negatively charged.

Question 4

What does each electron carry?

Answer 4

A tiny charge (Q).

Question 5

What is the unit for charge?

Answer 5

Coulomb (C).

Question 6

How do we measure a unit of charge of an electron?

Answer 6

We bundle billions of electrons into a coulomb.

Question 7

What is electric current?

Answer 7

It’s the number of coulombs of charge passing a point each second.

Question 8

What is the symbol for current?

Answer 8

I.

Question 9

What is the unit of current?

Answer 9

Amperes (A)

Question 10

What would 3C of charge passing through a bulb in 1 second be when translated into amperes?

Answer 10

3A.

Question 11

What is the formula for charge?

Answer 11

Q=It.

Question 12

Where could you find an electrical force field?

Answer 12

Around charged particles.

Question 13

What does the direction of an electric field mean?

Answer 13

It is the direction a positive particle would travel if placed in the field.

Question 14

What is electrical energy that a coulomb of charge is defined by?

Answer 14

Voltage/potential.

Question 15

What is the difference between the voltage/potential a coulomb has at one point or another?

Answer 15

It is called the potential difference (p.d.)

Question 16

What is potential difference measured in?

Answer 16

Volts.

Question 17

What does the voltage of a cell tell you?

Answer 17

The amount of energy the cell gives you or transfers to each coulomb of charge.

Question 18

What do coulombs do?

Answer 18

They carry the energy around a circuit.

Question 19

What is the voltage across a component?

Answer 19

It is the amount of energy a coulomb gives up at the component.

Question 20

What is energy measured in?

Answer 20

Joules

Question 21

How does d.c. from d.c. battery travel in a circuit?

Answer 21

The current is a constant size and travels in one direction from the negative side of the battery to the positive side.

Question 22

How does a.c. from a.c. battery travel in a circuit?

Answer 22

The current changes size and direction continually.

Question 23

How does a.c. travel in British homes?

Answer 23

The current changes direction in kettles and TVs 50 times each second (frequency 50 Hz).

Question 24

What things have a d.c. supply?

Answer 24

Car battery and watch battery.

Question 25

What things have a a.c. supply?

Answer 25

Electricity in your house.

Question 26

What is used to measure current?

Answer 26

Ammeter.

Question 27

What does the ammeter measure exactly?

Answer 27

The number of coulombs passing a point each second.

Question 28

What is used to measure voltage?

Answer 28

Voltmeter.

Question 29

What do all materials do in terms of resistance?

Answer 29

All materials oppose the flow of current (this is called resistance).

Question 30

What are the units for resistance?

Answer 30

Ohms.

Question 31

What happens as the resistance of a circuit increase?

Answer 31

The coulombs find it more difficult to flow meaning the current in a circuit decreases.

Question 32

How does the temperature of a component affect the resistance?

Answer 32

The higher the temperature the higher the resistance meaning the lower the current that is passing through.

Question 33

How does current act in a series circuit?

Answer 33

As there is only one path for the current to travel it stays the same all the time.

Question 34

How does voltage act in a series circuit?

Answer 34

The voltage across the whole circuit adds up to the supply voltage.

Question 35

How does current in a parallel circuit travel?

Answer 35

As there are multiple branches current travels through them until reaching the same current as the one that is in the supply.

Question 36

Where does electricity first flow in a parallel circuit?

Answer 36

The waves travel to the first available branch meaning more of the current will split off to this branch.

Question 37

What stays the same no matter where it is in a parallel circuit?

Answer 37

Voltage, It is equal to the supply voltage (even with resistors)

Question 38

Where are series circuits used?

Answer 38

Christmas lights (simple, cheap) safety switches on devices (avoid accidentally turning on device).

Question 39

Where are parallel circuits used?

Answer 39

Ceiling bulbs and plug points.

Question 40

What is Ohm’s Law?

Answer 40

It is the relationship between the current flowing through a component and the voltage across the component.

Question 41

What do the letters RT represent?

Answer 41

Total resistance.