Author Question: Superconductors have been discussed as a means for electrical energy storage. Because they are ... (Read 162 times)

mia · **on:** Jul 28, 2018

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 70 H, how much electrical energy (in kWh) could be stored?
a. 480 kWh
c. 690 kWh
b. 300 kWh
d. 970 kWh

Question 2

A string is strung horizontally with a fixed tension. A wave of frequency 100 Hz is sent along the string, and it has a wave speed of 100 m/s. Then a second wave, one of frequency 200 Hz, is sent along the string. What is the wave speed of the second wave?
a. 25.0 m/s
c. 70.7 m/s
b. 50.0 m/s
d. 100 m/s