Question

A gold wire carries a current of 76.2 mA.

(a) Find the number of electrons that flow past a given point in the wire in 10.4 minutes.
[Answer] electrons

b)In what direction do the electrons travel with respect to the current?
o opposite direction
o same direction
o The magnitude is zero.

Answer 1

#a

• Time=10.4min=10.4(60s)=624s
• Current=76.2mA=76.2×10^{-3}A=I

Now

• Charge=Q

$\\ \tt\Rrightarrow Q=\dfrac{I}{t}$

$\\ \tt\Rrightarrow Q=\dfrac{76.2\times 10^{-3}}{624}$

$\\ \tt\Rrightarrow Q=0.122\times 10^{-3}$

$\\ \tt\Rrightarrow Q=122\times 10^{-6}C$

$\\ \tt\Rrightarrow Q=122\mu C$

#b

• Same direction