To increase the current density in a wire of length l and ...

[savannahhooper]

To increase the current density in a wire of length l 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 2

The electron density in copper is 8.49  1028 electrons/m3 . The electron charge is e = -1.60  10-19 C. When a 1.00 A current is present in a copper wire with a 0.40 cm2 cross-section, the electron drift velocity, in m/s, with direction defined relative to the current density, is
 a. -1.84  10-6.
  b. +1.84  10-6.
  c. -1.84.
  d. -5.43  105.
  e. +5.43  105.

[vickybb89]

Answer to Question 1

B

Answer to Question 2

A