Question

Which of the following is non-ohmic resistance?

• A. Copper wire
• B. Brass wire
• C. Copper wire wound on an electromagnet
• D. Constantan wire

Answer 1

The correct option is B

Brass wire

Explanation for correct option(s):

(B) Brass wire

Non-ohmic resistance

1. Resistors that don't obey Ohm's law are called non-Ohm resistors.
2. Brass wire does not obey Ohm's law as the current through the wire is not directly proportional to the voltage across the wire.
3. Today, brass wires are used in instrumentation, aircraft, marine, and mechanical engineering, electrical engineering (for manufacturing cables, wires, transformers, and coils), shoe industry (for manufacturing brass nails), and welding (high-strength). Suture material) used.

Explanation for incorrect option(s):

(A) Copper wire

1. Copper is used as a conductor in a variety of electrical systems and obeys Ohm's law,
2. Copper wire is used in a variety of applications, including power production, transmission, distribution, telecommunications, electronic circuits, and a variety of other electrical devices.

(C) Copper wire wound on an electromagnet

1. To prevent electricity from traveling between the wires, the copper wire is wound around the electromagnet.
2. If the wire isn't wounded, the current will take a shortcut and won't loop back around the core several times.
3. There is no magnetic field created if no current travels through the loop.
4. This wire follows Ohm's law.

(D) Constantan wire

1. $55\%CU/45\%$NI Constantan Wire Constantan is a copper-nickel alloy used in the manufacture of thermocouples, thermocouple extension wires, precision resistors, and low-temperature resistance heating applications.
2. This wire follows Ohm's law.

Thus, option B is the correct answer.