1. Potential Difference, Current and Resistance
Voltage
Current
Resistance
How to Measure Voltage, Current and Resistance

2. Potential Difference
Voltage (V) = The source of energy in a circuit provides energy to the electrons. It is how much energy that the electrons pick up from the source.
igher the potential difference (voltage) the greater the potential energy of each electron
PD – another words = voltage
A battery had potential energy in the electrolyte of its electrochemical cells
The chemical in the electrolyte react with the electrode that causes a difference in the amount of electrons between the two terminals
One end has a negative charge (electrons) and the other end had the positive charge
The ngative electrons are attrached to the positive end of the battery and move toward it throught the use of a conductor (ie copper wire)
like falling apple from a tree
PD – causes current to flow in a closed circuit

3. Measuring Voltage
Volt (V) – is the unit used to measure potential difference Voltmeter- is connected in parallel
What is the apparatus used to measure potential difference?
Placing the two end of the voltmeter and measure the potential differnece in a battery

4. Current
Current (I) = is the how fast electrons are moving through the circuit.
Think of the continuous flow of electric current like water flowing in a stream
The water keeps flowing unless the source dries up
As long as the battery continues to separate charges on its terminals (ends) the electrons will continue to flow
WB – example of DC
WB – example of alternating current

5. Measuring Current
The electric current is measured in units called – Ampere (A) Ammeter- measures current in a circuit. An ammeter is connected is series.
Current
Energy moving past a point in the circuit every second

6. Resistance ALL SUBSTANCES RESIST ELECTRON FLOW
Resistance (R)- to slow the movement of electrons in a circuit
ALL SUBSTANCES RESIST ELECTRON FLOW
Conductors have low resistance values
Insulators have high resistance values
When a substance resists the flow of electrons, it slows down the current and converts the electrical energy into other forms of energy
The more resistance a substance has they more energy is gains from electrons that pass through it
The energy gains by the substance is radiated to its surroundings as heat and/or light energy
The more resistance a component has the smaller the conductivity

7. Measuring Resistance Ohm (Ω) – the unit used to measure resistance
Ohmmeter
Measures electrical resistance
Multimeter = measures differnece, current, or resistance
Ohm – greek leter omega