Question

# The resistivity of gold is 2.44\times 10-8 ?\times m at a temperature of 20°C. Agold wire, 0.5 mm in diameter and 44 cm long, carries a current of380

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The resistivity of gold is $$\displaystyle{2.44}\times{10}-{8}?\times{m}$$ at a temperature of $$20^{\circ}C$$. Agold wire, 0.5 mm in diameter and 44 cm long, carries a current of 380 ma. The number of electrons per second passing a given crosssection of the wire, is closest to:
a. $$2.4 \times 1018$$
b. $$2.8 \times 1014$$
c. $$1.2 \times 1022$$
d. $$2.4 \times 1017$$
e. $$6.3 \times 1015$$

Given that resistivuty is ? $$\displaystyle={2.44}\times{10}-{8}?\times{m}$$
$$Length(L) = 0.44m\ radius(R)= (\frac{D}{2}) = 0.25\ mm = 0.25\times 10^{-3}m$$
We know the formula for the resistance is $$\displaystyle{R}=?\frac{{L}}{{A}}={5.47}\times{10}-{2}?$$
Given $$I = 0.380A$$
We know the formula is $$\displaystyle{I}=\frac{{q}}{{t}}=\frac{\ne}{{t}}{n}={I}\frac{{t}}{{e}}={2.4}\times{10}$$