Question

Which of the following obeys Ohm's law?

• A. Copper wire
• B. Filament of bulb
• C. Diode
• D. Carbon resistor

Hint:

For materials that obey Ohm’s law, resistance remains constant regardless of applied voltage.

Answer 1

The Correct Option is A

Step 1: Ohm's Law.
Ohm's law states that the current through a conductor is directly proportional to the voltage across it and inversely proportional to the resistance. Mathematically: \[ V = IR \] Step 2: Checking the materials.
Copper wire obeys Ohm’s law as its resistance remains constant with applied voltage.
Filament of a bulb and a diode do not obey Ohm’s law because their resistance changes with voltage.
Carbon resistors generally obey Ohm's law but are less ideal than metals like copper.
Step 3: Conclusion.
Copper wire is the material that follows Ohm's law as its resistance remains constant over a wide range of voltages.