To increase the current density in a wire of length and diameter D, you can:
A)decrease the potential difference between the two ends of the wire.
B)increase the potential difference between the two ends of the wire.
C)decrease the magnitude of the electric field in the wire.
D)heat the wire to a higher temperature.
E)combine both (b) and (d).

Question

To increase the current density in a wire of length and diameter D, you can: 
A)decrease the potential difference between the two ends of the wire. 
B)increase the potential difference between the two ends of the wire. 
C)decrease the magnitude of the electric field in the wire. 
D)heat the wire to a higher temperature. 
E)combine both (b) and (d).

Quizplus · Accepted Answer

According to Ohm's Law, current density (J) is directly proportional to electric field strength (E) and inversely proportional to resistivity (ρ) of the material. Therefore, in order to increase current density, we need to increase the electric field strength. This can be achieved by increasing the potential difference (V) between the two ends of the wire, as E = V/L, where L is the length of the wire. Therefore, increasing the potential difference is the best choice.

To Increase the Current Density in a Wire of Length