STELR - revision sheets

A current is the flow of electrons. It is measured with an ammeter. Units are in amps.

Voltage is the force at which the current is pushed around the circuit. 240V has a greater push than 3V. We measure voltage with a voltmeter. Units are in volts

The unit of power is the Watt. It can be determined by multiplying the voltage by the current.
When we use electricity at home we are supplying a voltage to force the current through our wires to run TVs etc.
A common measurement is 240V x 10 amps = 2400 Watts of power. OR 2.4kW. Because we use this power over a period of time we often try to convert these measurements to kilo Watt hours - kWHr. This means how many kW are used per hour.

Examples of conduction

STELR project

So What CAN you do?

A 14-year-old New York student was named "America's Top Young Scientist" for inventing a solar-powered water jug that changes dirty water into purified drinking water.

Resource links

STELR wind turbine circuit for measuring power

Hand crank generator

STELR solar panel series power

STELR project - Project outline

Presenting your work -

Unless you have negotiated an alternative with me you must
1. Answer all the questions
2. Use the information from most of the questions in a to make a series of diagrams that addresses the 5 main questions.
  • You must add the diagrams to the collaboration site
  • you must be able to present the information you found by showing the class the diagrams and telling the class how these energy sources are transformed into electricty.

What do you hand in (each pair)

- All the research you have completedin the form of notes should be kept for the exams.
You will need to submit the diagrams that formed the basis of an answer for you and your partner to the collaboration site
  1. Diagrams needs to be submitted via wikispaces at our collaborative project site (see the link below)-- Clearly mark the topic and your names on the project - we will be using your information to study for the end of semester exam.

When is this Due

Wed 19th February

Class Notes on Electricity
Using the multimeter in voltmeter and ammeter mode
You will need to make some notes about the following.
What is measured by the multimeter.
What are the units of the measurement?
Draw a circuit showing how the voltmeter needs to be set up in a circuit to measure voltage.
Draw a circuit showing how the ammeter needs to be set up in a circuit to measure current.

To calculate Power we need to multiply Voltage by Current.
the formula is
P = VI

Now REad worksheet 3 page 36 and 37 and answer question p 38
do practical activities 4 p 39 to 46

When we hooked up the batteries in series the light went brighter. We noticed the current increased and the voltage doubled.

When the batteries were in parallel we noticed the light was about the same brightness and the voltage and current stayed the same.

Using the formula for power we can predict that batteries in series will increase the power output. Batteries in parallel will have about the same power output as a single battery.

Revision Questions

  1. What is the difference between the natural greenhouse effect and the enhanced greenhouse effect?
  2. Give an example where KE is converted to electrical E
  3. GPE is converted to KE
  4. Where GPE is converted to KE and KE is converted to electrical E
  5. Draw a circuit with 2 lights and a battery and a switch. Position the lights so they are in parallel
  6. Wind energy can be converted to electrical energy. How?
  7. What are the disadvantages of wind power and solar power
  8. What are the advantages of wind power and solar power
  9. How do you measure voltage in a circuit - add a V to the circuit you drew in ques 5 to show the position of the voltmeter.
  10. How do you measure current in a circuit - add a A to the circuit you drew in ques 5 to show the position of the ammeter.