Question

A section of superconducting wire carries a Current of loo A and requires 100 L of liquid nitrogen per hour to keep it below its critical tern1 to be economically advantageous to use a superconducting wire, the cost of cooling the wire must be less than the cost of energy lost to l Assume that the cost of liquid nitrogen is $0.30 per liter, and that electric energy costs $0.10 per kWh. What is the resistance of a normal as much in wasted electric energy as the Cost of liquid nitrogen for the superconductor? Omega

Answer 1

here ,

cost of cooling using liquid nitrogen , C = cost of liquid N2 per litre * volume

C = 0.30 $ * 1

C = 0.30 $ per hour

Now, energy used for 0.30 $

energy = 0.30/0.10

energy = 3 kW.h

now,the power in the wire can be 3 kW

let the resistance is R ,

Power = i^2 * R

3000 = 100^2 * R

R = 0.3 ohm

the resistance of wire can be 0.3 Ohm