P2 Electricity

Lessons 11-14

L11 – More on Power

L12 – The National Grid

L13 – Series and Parallel circuits using software

L14 – Questions from topic

L11 – More on Power

Objective

To be able to use the equation

E=QV to calculate the energy

transfered.

To be able to use the equation

P=VI to calculate the power used.

L11 – More on Power

When ever electrical charge goes through a change in potential difference the

energy is being transferred.

Energy is supplied with the change at the battery to give it a potential

difference

When the charge goes through a component lets say a bulb the energy falls as

it is transferred to the bulb to light it up

L11 – More on Power

Example

Question

The motor on an electric scooter is attached to a 12 V battery. 300C of

change passes through the circuit as it is used. Calculate the energy

transferred.

Step 1 = Calculation =

Step 2 = Substitute numbers =

Step 3 = Answer =

Step 4 = Units =

Answer

The motor on an electric scooter is attached to a 12 V battery. 300C of

change passes through the circuit as it is used. Calculate the energy

transferred.

Step 1 = Calculation = E=QV

Step 2 = Substitute numbers = E = 300 x 15

Step 3 = Answer = 4500

Step 4 = Units = 4500 J

L11 – More on Power

As well as energy transferred in a given time, the power of an appliance can

be found using the equation:

Questions

More E=QV questions

to practice

Answers

L12 – The national Grid

Objective

To understand how the electricity in

your home gets there

L12 – The national Grid

L12 – The national Grid

L12 – The national Grid

Video link

https://youtu.be/iNvGiTn64fQ

L13 – Series and parallel circuits

practical

Objective

To use software to model what

happens in a series and parallel

circuit

L13 – Series and parallel circuits

practical

Go to the link at the bottom of the page and follow the video on the next

slide

https://phet.colorado.edu/en/simulation/circuit-construction-kit-dc

L13 – Series and parallel circuits

practical

L13 – Series and parallel circuits

practical

When you have manage to build the series and parallel circuits in the video make the following circuits with the correct components included.

For each circuit record the current of each bulb.

For ach circuit record the voltage of the across the blub

1- 2 batteries, a switch, 2 bulbs in series

2 – 2 batteries a switch and 2 bulbs in parallel, the switch must switch off both bulbs

3 – 1 battery and 1 bulb in series

4 – 1 battery 1 bulb and 1 switch in series

5 – 2 batteries a switch and 4 bulbs in parallel, the switch must switch off only 1 bulb

Calculations

Using the equation P=IV calculate the power of each of the bulbs in your

circuit using the potential difference from your voltmeter and the current

from the ammeter

P=IV

When you have finished

Play around with the software on the website see what you can do with the

tools provided.

L14 –Questions for P2

Work your way through the statements on the next three slides, if you can

answer the question tick it off if you cannot then go back to the PowerPoint

for that lesson find the answer.