Question

Superconductors are substances which

• A. Offer no resistance to the flow of electricity
• B. Offer high resistance to the flow of current
• C. Conduct electricity at high temperatures
• D. Conduct electricity at low temperature

Hint:

Recall that below a critical temperature, superconductors show exactly zero electrical resistance.

Answer 1

The Correct Option is A

A superconductor is a special material that, when cooled below a certain critical temperature, loses all electrical resistance completely.

Because the resistance drops to exactly zero, an electric current can flow through a superconductor without losing any energy as heat, and the current can even persist for a very long time once started, without any external source pushing it. This property of offering no resistance to the flow of electricity is the defining feature of a superconductor.

Option B is wrong because it describes the exact opposite behavior. A superconductor is defined by having no resistance, not high resistance.

Option C is wrong because superconductivity usually appears at very low, not high, temperatures, since normal thermal vibrations at high temperature disturb the special state needed for zero resistance.

Option D is wrong on its own even though it mentions low temperature, because merely conducting electricity at low temperature is not special. Every good conductor still conducts at low temperature. The defining property is the complete disappearance of resistance, which option D does not state.

The correct answer is that superconductors offer no resistance to the flow of electricity.