Resistance

• Resistance is the ratio of potential difference across a component to the current flowing through it
• A superconductor is a material with zero resistance when below transition temperature
• Transition temperature is the temperature where resistance becomes zero
• There is no energy transfer in superconductors as electrons do not collide with metal ions
• Ohm's law states that the potential difference across a component is directly proportional to the current flowing though it
• A protective resistor is used with an LED to prevent overheating
• Resistance of an LDR decreases as light intensity increases
• Resistance of a thermistor decreases as temperature increases
• Power is the work done per unit time