A-LEVEL Physics: 5.1.5 & 5.1.6 & 5.1.7: Superconductivity (Seneca)

Question 1

What are ‘Superconductors’?

Answer 1

Superconductors are Materials with a Resistivity Below a Critical Temperature. They are Conductors with 0 Resistance.

Question 2

Because the Resistance of a Piece of Superconductor is Zero, …

Answer 2

No Heat is Lost as Current Flows Through them.
This Means that Current Could Flow Forever. (no Heat Loss means No Resistance)(no Resistance means no Heat Loss).

Question 3

Why is the Use of Superconductors Limited?

Answer 3

Because Most Superconductors Must be Cooled to Temperatures just above Absolute 0 Kelvin. This is Very Expensive, & so Limits the Use of Superconductors.

Question 4

Why are Superconductors very Useful?

Answer 4

Because they have 0 Resistance.

Question 5

Explain exactly how Superconductors have 0 Resistance: (3)

Answer 5

-Superconductors Occur when the Free Electrons Combine to Form Cooper Pairs at Low Temperatures.

-These Cooper Pairs Collide with the Other Atoms in the Material, & if the Energy of the Collision is Low, then the Cooper Pairs do Not Split & Lose Energy.

-This means that the Resistivity of the Superconducting Material is 0.

Question 6

Moving Charges Produce…

Answer 6

Magnetic Fields.

Question 7

Moving Charges Produce Magnetic Fields.
What happens if the Charges Move Less?

Answer 7

If the Charges Move Less, the Magnetic Field Strength Reduces.

Question 8

Moving Charges Produce Magnetic Fields.
What Must there be to Maintain a Large Magnetic Field?

Answer 8

There Needs to be a Constant Movement of Charge to Maintain a Large Magnetic Field.

Question 9

Magnets Made of Superconductors have Zero Resistivity. Why is this?

Answer 9

This is so that Once Currents have been set up, they Continue Without Loss of Energy (due to 0 Resistance).

Question 10

Because Superconductors have 0 Resistance, they Can Reduce…

Answer 10

Energy Loss in Energy Transmissions.