Superconductors have been discussed as a means for electrical energy storage.Because they are resistanceless,a current once started in a loop would continue without loss.If a current of 1.0 × 10⁴ A were started in a huge toroidal coil of radius 1.0 km and inductance 50 H,how much electrical energy (in kWh)could be stored?

Question

Quizplus · Accepted Answer

The energy stored in an inductor is given by the equation:
E = 1/2 * L * I^2
where E is the energy stored, L is the inductance, and I is the current.
Plugging in the values given in the problem, we get:
E = 1/2 * 50 * (1.0 × 10^14)^2
E = 2.5 × 10^29 J
To convert joules to kWh, we divide by 3,600,000:
E = 6.94 × 10^22 kWh
Rounding to two significant figures, we get:
E = 690 kWh

Superconductors Have Been Discussed as a Means for Electrical Energy