What would be the resistivity of a perfect conductor in ohm-meters?

0

1

100

Infinity

A current of 3.50 A flows through the leads of an electric appliance. How long does it take for 6.50 C of charge to pass through the leads?

1.8 s

22.8 s

0.5 s

10 s

The resistance of a perfect conductor is 0 Ohm, so the resistivity is necessarily also 0 (Ohm. meter). Resistivity = Resistance * (length) / (cross-section area).

Use the current-charge-time formula:

Current = (amount of charge) / (time) = 6.5C / t = 3.5A

so t=6.5C/3.5A = 1.86 seconds

The closest answer choice is 1.8s (but it really should have been 1.9s)