Equipment Electric circuit boxes Voltmeters Ammeters Potential Difference

Equipment Electric circuit boxes Voltmeters Ammeters

Potential Difference L. A. : Measure potential difference in a 4 circuit. 6 Calculate the potential difference 8 Rearrange equations for resistance and potential difference.

Starter Spelling test! Circuit Ammeter Component Conductor Resistance Coulomb Voltage

Current and charge Potential difference and resistance Component characteristics Series Circuits Electric circuits Parallel Circuits

Potential Difference (V) Potential difference is the energy transferred or ’work done’ by each coulomb of charge as it passes through a component. Cells (or batteries) give the electrons energy (provide the push). When the electrons pass through a component they transfer some of the energy. E. g. in a lamp the energy transfer to Heat and light

Key info Potential Difference (Also known as voltage) Symbol: V Measured in: Volts SI Unit: E. G V V = 20 V

Build it How is the placement of the voltmeter different from how you put the ammeter in last lesson? 1 2

All the joules given by the battery to the electrons are exactly used up by the time the electrons get back to the battery! If there is more than one lamp what would have to happen?

Potential difference = Energy / Charge (in V) (in J) (in C) or V =E/Q E Q V f o r e b Num es per. e. i l ( u b o j m y o l cou energ each the ied by f r o r a b c lom cou trons) c e l e

Question 1 A battery transfers 30 J for every coulomb of charge that passes through the battery. What is the potential difference of the battery?

Question 2 A battery has a voltage rating of 40 V. How much energy is transferred by the battery if 20 C of charge pass through the battery?

Task 1. What is the voltage of a battery if it transfers 40 J of energy for every 10 C that pass through it? 2. A builder requires a 400 V battery to power his pneumatic drill. He is told that a battery transfers 1000 J for every 3 C of charge that pass through it. Will this battery be good enough? Why? 3. How much energy would the battery in the question above need to transfer for every 3 C to have a voltage of 400 V? 4. Battery A has a rating of 300 V. Battery B has a rating of 500 V. What is the difference in the amount of work done by the two batteries if 20 C of charge pass through both batteries?

Plenary - Conservation of Energy Question: You can get different currents with the same battery, depending on what you connect to it. What difference will the size of the current make to the lifetime of the battery? (how long the battery will run for) Why?