Yr9 Electricity

Question 1

What is Electricity

Answer 1

The flow of electrons through a conducting path

Question 2

What is DC

Answer 2

Direct Current, electric current that flows in one direction from negative to positive

Question 3

What is AC

Answer 3

Alternating Current, electric current that changes direction 50 times per second. It can be transported more efficiently over longer distances so it is used in the grid

Question 4

Series Circuit

Answer 4

A circuit which is connected in sequence with only one possible path

Question 5

Parallel Circuit

Answer 5

A circuit which is connected in parallel with multiple possible paths

Question 6

Advantages of Parallel Circuits

Answer 6

In a parallel circuit each component gets the full voltage as opposed to the voltage being split in series circuits. Each component connected in parallel can also be switched on and off individually which is not possible when connected in series. This fact also makes parallel circuits easier to troubleshoot

Question 7

Voltage

Answer 7

Measure of the electrical energy or force carried by the charges in the circuit, also known as potential difference. It is measured in Volts or V

Question 8

Current

Answer 8

The amount of electricity or electrons going past a given point per second. Measured in Amperes, Amps or I

Question 9

Resistance

Answer 9

Measure of how difficult it is for electricity to flow through a material. Measured in Ohms, written as the Greek Omega.

Question 10

Ohms Law

Answer 10

A law which describes the relationship between Voltage, Current and Resistance. V = IR with V = Voltage, I = Current and R = Resistance

Question 11

How does Electricity work

Answer 11

Many metals have only a few electrons in the outer shell. These electrons aren’t as tightly bound so they can swap places with the electrons of other atoms. When force is applied the electrons are driven down the metal in one direction creating a current

Question 12

What is Power

Answer 12

Measure of electrical power. Power = Voltage * Current and it is measured in watts

Question 13

Characteristics of Black Coal

Answer 13

-Older
-Higher in value
-Lower Moisture Content
-High Chemical Potential Energy
-Creates less pollution when burnt

Question 14

Characteristics of Brown Coal

Answer 14

-Cheap
-High Moisture Content
-Lower Chemical Potential Energy
-Creates more pollution when burnt

Question 15

Electric Motors

Answer 15

When a wire carrying a current is placed in a magnetic field there is an upward force. Another wire with the current going opposite the first will have a downward force. If the wires are connected in a coil they will spin. The same idea can also work in reverse to create electric generators.

Question 16

2 Amperes = ??? Coulombs per second

Answer 16

2

Question 17

Conductors vs Insulators

Answer 17

Conductors are materials that electricity can easily travel through
Insulators are materials that electricity can not easily travel through.

Question 18

Fuses vs Circuit Breakers

Answer 18

A fuse is a device which breaks when too much current is going through the circuit in order to prevent short-circuit
A circuit breaker is a switch that performs the same function as a fuse and can also be reset while fuses must be replaced

Question 19

What is a Short-Circuit

Answer 19

A short circuit is a type of electrical malfunction where electricity goes down an unintended path with little to no resistance. This can cause fires or electrocutions. The opposite is an open circuit where electricity cannot flow at all.

Question 20

Voltmeter

Answer 20

Measures voltage, should be connected in parallel to the area being measured.

Question 21

Ammeter

Answer 21

Measures current, should be in the flow. (connected in series)