Analysis of Current-Voltage Graphs for Different Components

This page presents the current-voltage graphs for a resistor, filament lamp (bulb), and diode, along with evaluations of their characteristics.

For a resistor:

• The graph is a straight line passing through the origin.
• Potential difference is directly proportional to current, following Ohm's Law.
• Resistors are ohmic conductors with fixed resistance.

Definition: Ohm's Law states that the current through a conductor is directly proportional to the voltage across it, given that physical conditions remain constant.

For a filament lamp:

• The graph is curved, showing a non-linear relationship.
• As voltage increases, current increases at a decreasing rate.
• The lamp's resistance increases with temperature due to increased ion vibration and electron collisions.

Highlight: A filament lamp is not an ohmic conductor because its resistance changes with temperature.

For a diode:

• The graph shows current flow in only one direction.
• At low voltages, the diode has high resistance.
• Current begins to flow rapidly once a certain voltage threshold is reached.

Vocabulary: Safety resistor - A resistor used in a diode circuit to prevent excessive current flow.

Example: The diode graph shows zero current for negative voltages, illustrating its unidirectional conduction property.