Electricity

Question 1

What are the two types of charge?

Answer 1

Positive and negative.

Question 2

What cause a negative charge?

Answer 2

The presence of electrons.

Question 3

What are some examples of good conductors?

Answer 3

Copper, aluminium, steel and graphite.

Question 4

Is it fair to say that ALL metals are electrical conductors?

Answer 4

Yes!

Question 5

What are some examples of insulators?

Answer 5

Plastic, wood, glass, and rubber.

Question 6

Why are conductors able to carry charge?

Answer 6

Because they have free electrons which can move to carry the charge.

Question 7

Are there any free electrons inn insulators?

Answer 7

No!

Question 8

What is conventional current?

Answer 8

Flow from the POSITIVE to the NEGATIVE terminal.

Question 9

What is electron flow?

Answer 9

Flow from the NEGATIVE to the POSITIVE terminal.

Question 10

A collection of two or more cells is known as a what?

Answer 10

A battery.

Question 11

What is a switch used for?

Answer 11

To create an ARTIFICIAL BREAK in a circuit which will prevent the flow of current.

Question 12

What is a resistor?

Answer 12

A component which will restrict (but not fully stop) the flow of current in a circuit.

Question 13

What is the difference between a FIXED and a VARIABLE resistor?

Answer 13

A fixed resistor has a SET VALUE of RESISTANCE, whereas a variable resistor is one which you can VARY the VALUE of RESISTANCE.

Question 14

What does a VOLTMETER measure?

Answer 14

The voltage across a component in a circuit.

Question 15

Does current flow through a voltmeter? Why?

Answer 15

It possess a very HIGH resistance meaning NO CURRENT will flow through it.

Question 16

What does an AMMETER measure?

Answer 16

The current through the circuit.

Question 17

How must an AMMETER be placed?

Answer 17

In series.

Question 18

How must a VOLTMETER be placed?

Answer 18

In parallel.

Question 19

What is the use of a lamp or bulb in a circuit.

Answer 19

It is a source of light.

Question 20

What is a FUSE?

Answer 20

A component which is used to CREATE A BREAK in a circuit if there is TOO MUCH CURRENT FLOWING.

Question 21

What is voltage?

Answer 21

The energy transferred per coulomb of charge.

Question 22

What can voltage also be known as?

Answer 22

Potential difference.

Question 23

What is current?

Answer 23

The flow of electric charge in a circuit.

Question 24

What is the quote which links energy, potential difference and coulomb of charge?

Answer 24

One volt is the potential difference that would result in one joule of energy being transferred per one coulomb or charge.

Question 25

What happens between two objects that have the SAME charge?

Answer 25

They REPEL each other.

Question 26

What happens between two objects that have OPPOSITE charges?

Answer 26

The will ATTRACT each other.

Question 27

What is the equation for electric charge?

Answer 27

Q = I x t Charge (C) = Current (A) x time (s) MUST BE SECOND!!!

Question 28

What is charge measured in? What is its unit?

Answer 28

Charge is measured in COULOMBS (C) and given the symbol Q.

Question 29

What is current measured in? What is its unit?

Answer 29

Current is measured in AMPERES (AMPS) (A) a given the symbol I.

Question 30

What are the two conditions that MUST be met before an electric current will flow:

Answer 30

-MUST be a COMPLETE CIRCUIT i.e no breaks/gaps. -MUST be a SOURCE OF ENERGY e.g cell, battery or the mains power supply.

Question 31

What is the equation for resistance?

Answer 31

R = V/I Resistance = Voltage/I

Question 32

What is RESISTANCE measured in?

Answer 32

Ohms!

Question 33

What factors impact the resistance of a conductor? (4)

Answer 33

1. The MATERIAL from which the wire is made 2. The LENGTH of the wire 3. The CROSS-SECTIONAL AREA of the wire 4. The TEMPERATURE

Question 34

How do you find the resistance in a SERIES circuit?

Answer 34

R total = R1 + R2 + R3

Question 35

How do you find the resistance in a PARALLEL circuit?

Answer 35

1/R total = 1/R1 + 1/R2 =1/R3

Question 36

When calculating the resistance in a PARALLEL circuit: what is the final step?

Answer 36

FLIP the equation.

Question 37

When resistors are connected in series… (2)

Answer 37

-The current in each resistor is the SAME -The SUM of the VOLTAGES across EACH RESISTOR is EQUAL to the BATTERY VOLTAGE.

Question 38

When resistors are connected in PARALLEL?

Answer 38

-The voltage across each resistor is the same as the voltage provided by the battery -The sum of the currents in each resistor is equal to the current coming from the battery.