2.1 Potential Difference and Resistance & 2.2 Current Flashcards
What is potential difference?
The cell/battery provides the push to make charges move. A battery with a larger potential difference transfers more energy.
What does the potential difference across a cell tell you?
- The size of the force on the charges
- the energy transferred by the cell to the charges
- the energy transferred by the charges to components in the circuit.
How do you measure potential difference?
Using a voltmeter. Measured in volts (V). You can measure the potential difference of a component by connecting a voltmeter across it.
What is resistance?
Each component has a different resistance which tells you how difficult it is is for charges to pass through. It is measured in ohms (Ω).
How do you calculate resistance?
Resistance (Ω) = potential difference (V) / current (A)
What happens to potential difference in series and parallel circuits?
The potential difference is the same anywhere in a series or parallel circuit.
What happens when you add bulbs in a series circuit?
The bulbs get dimmer.
What happens if you add bulbs in a parallel circuit?
The bulbs we be the same brightness as long as they are in separate loops.
What is current?
The amount of charge (charged particles) flowing per second. You measure currents in amperes or amps (A) with an ammeter. It flows from positive to negative terminals of a battery.
