Ohmic conductors and IV characteristics

What is an ohmic conductor?

A resistor in which the current is directly proportional to the potential difference at a constant temperature e.g.

What resistance do ohmic conductors have?

Constant resistance

How does the resistance in an ohmic conductor change?

At a constant temperature

How does resistance increase with a filament lamp?

When an electrical charge flows through a filament lamp

How does resistance increase with a diode?

The resistance depends on the direction of the current. Current will flow normally in the correct direction but reversed it will have a very high resistance

How do you find a component's I-V characteristic?

1) Set up the test circuit
2) Vary the variable resistor - this alters the current flowing through the circuit and the potential difference across the component
3) Take several pairs of readings from the ammeter and voltmeter to see how the potential difference varies as the current changes
4) Swap over the wires connected to the battery

What is the graph for the ohmic conductor (resistor)?

Directly proportional

What is the graph for the filament lamp?

As the current increases

What is the graph for the diode?

Current will only flow through a diode in one direction. The diode has a very high resistance in the reverse direction