PhysicsCode 5054
Resistance
What this topic asks you to be able to do
- Recall resistance = p.d. / current, R = V / I, and use this equation
- Describe an experiment in which a voltmeter and an ammeter are used to find resistance, then carry out the suitable calculations
- Recall that a wire's resistance is directly proportional to its length and inversely proportional to its cross-sectional area, and use these relationships
- Give Ohm's law, including the requirement that temperature stays constant
- Sketch, and account for, the current–voltage graphs of a resistor whose resistance stays constant, a filament lamp and a diode
- Describe how raising the temperature of a resistor, such as the filament of a filament lamp, affects its resistance