Section 2- Electricity

Question 1

2.2

+What are the hazards of Long cables?

Answer 1

You could trip over them.

Question 2

2.2

+What are the hazards of damaged plugs?

Answer 2

Electrocution from live wires sticking out

Question 3

2.2

+What are the hazards of having water around sockets?

Answer 3

Electrocution as water conducts electricity.

Question 4

2.2 understand and identify the hazards of electricity including frayed cables, long cables, damaged plugs, water around sockets and pushing metal objects into sockets

+What are the hazards of a frayed cables?

Answer 4

Electrocution from live wires.

Question 5

2.3 understand the uses of insulation, double insulation, earthing, fuses and circuit breakers in a range of electrical appliances

+What is insulation?

Answer 5

A layer of non-conducting material placed around a conducting material.

Question 6

2.3

+What is double insulation?

Answer 6

Two layers of insulation- a precaution that makes sure that a live wire cannot touch the casing (no electric shock).

Also means that the casing if the of the appliance is plastic therefore no electric shock.

Question 7

2.3

+What is earthing?

Answer 7

A wire connected from an appliance to the ground to allow current to flow safely away, if there is a fault.

Question 8

2.3

+What are fuses?

Answer 8

A thin piece of wire that melts and cuts the current if a too high of a current flows through it.

A fuse in appliances will usually be a tiny bit higher than the voltage of the appliance.

Question 9

2.3

+What is a circuit breaker?

Answer 9

A switch that cuts the circuit if a too high of a current flows through it.

More expensive than fuses but they can be reset.

Question 10

2.4 understand that a current in a resistor results in two electrical transfer of energy and an increase of temperature;

+How can this be used in a variety of domestic appliances?

Answer 10

As a resistor slows down the movement of electrons, the kinetic energy that was moving them is converted into heat energy. This can be for example is hair dryers.

Chemical energy converted to electrical energy, causing a current. Energy transferred from the battery around the circuit by current.

Resistor converts electrical energy into thermal energy. The resistor gets hot.

Question 11

2.4

+What is the effect of a resistor in domestic appliances? (To examples)

Answer 11

Thin wires in light bulbs heat up with current and therefore give off light.

Heaters have wires which get hit with a current and therefore gives off heat.

Question 12

2.4

+What is the effect of a resistor?

Answer 12

The resistor gets hotter with the current flow.

Question 13

2.2

+What are the hazards of pushing metal objects into sockets?

Answer 13

Electrocution as metal conducts electricity.

Question 14

2.5 know and use the of power and apply relationship to selection of appropriate fuses

+What is the equation for power?

Answer 14

Power[w] = voltage [v] X current [A]

P=VI

Question 15

2.7 understand the difference between mains electricity being alternating current(a.c) and direct current (d.c) being supplied by a cell or battery

+What is a.c?

Answer 15

A.C stands for alternating current.

It is supplied form mains electricity.

Alternating current changes from one direction to another rapidly.

Mains electricity is alternating.

Question 16

2.7

+What is d.c?

Answer 16

D.C stand for direct current

It is supplies by cells and batteries.

Direct current only flows in one direction.

D.C comes out as a straight line on a oscilloscope.

Question 17

2.6

+What is the equation for energy transferred?

Answer 17

Energy transferred = voltage[v] x current[A] x time[s]

E=VIT

Question 18

2.8 explain why a series or parallel circuit is more appropriate for particular application, including domestic lighting.

+Why is a parallel circuit more appropriate?

Answer 18

• If one bulb breaks the others stay on.
• In a parallel circuit different components are connected separately to the supply.
• If one component breaks the others continue to work, the rest of the circuit is being powered.
• Good for charging higher power, potential difference is equal all over the circuit, meaning that each component receives full voltage.

Question 19

2.8

+Why is a series circuit more appropriate?

Answer 19

• One bulb breaks they all break.
• In a series circuit everything is connected on one line.
• The voltage is shared out between every component which makes it useful for supplying low power things like fairy lights.

Question 20

2.9 undestand that the current in a series circuit depends on the applied voltage and nature of the other components

Answer 20

-The current is a series circuit is the same through out all the [arts of the circuit, I1=I2=I3.
-Worked out by using the equation:
I=V/R
-So it’s the total of voltages received by the components divided by the total resistance of all the components resistance.