What is the term for a device that does not obey Ohm's Law?

What is the term for a device that does not obey Ohm's Law?

• A. Ohmic
• B. Non-Ohmic
• C. Wires
• D. Resistors

Answer: (B)

Ohm's Law describes a constant resistance where current is proportional to voltage. When a component’s resistance stays the same (for example, a simple resistor at a constant temperature), doubling the voltage doubles the current, giving a straight-line V–I relation. If the resistance changes with voltage or current, the current no longer increases in direct proportion to the voltage. Such devices don’t follow Ohm's Law and are called non-Ohmic. A common example is a filament lamp: as current rises, the filament heats up, its resistance increases, so the V–I relationship bends instead of forming a straight line. Diodes also behave non-Ohmically, conducting strongly in one direction with a nonlinear V–I curve. Because it describes this non-proportional behavior, the correct term is non-Ohmic.

Ohm's Law describes a constant resistance where current is proportional to voltage. When a component’s resistance stays the same (for example, a simple resistor at a constant temperature), doubling the voltage doubles the current, giving a straight-line V–I relation.

If the resistance changes with voltage or current, the current no longer increases in direct proportion to the voltage. Such devices don’t follow Ohm's Law and are called non-Ohmic. A common example is a filament lamp: as current rises, the filament heats up, its resistance increases, so the V–I relationship bends instead of forming a straight line. Diodes also behave non-Ohmically, conducting strongly in one direction with a nonlinear V–I curve. Because it describes this non-proportional behavior, the correct term is non-Ohmic.