Question

If ${10}^{20}$ electrons flow from the black body to the red body through the copper wire in 8 seconds, then find the current flowing between them.

• A. 2 A
• B. 0.2 A
• C. 8 A
• D. 1 A

Answer 1

The correct option is A 2 A

Given:
Number of electrons flown, $n={10}^{20}$
Time taken, $t=8s$

Charge on a single electron is:
$e=-1.6\times {10}^{-19}C$
Total charge through the wire,
$Q=ne$
$Q=-1.6\times {10}^{-19}\times {10}^{20}$
$Q=-16C$

Current through the wire:
$I=\frac{Q}{t}$
$I=\frac{16}{8}=2A$