## An eighteen gauge copper wire has a nominal diameter of 1.02mm. This wire carries a constant current of 1.67A to a 200w lamp. The density of

Question

An eighteen gauge copper wire has a nominal diameter of 1.02mm. This wire carries a constant current of 1.67A to a 200w lamp. The density of free electrons is 8.5 x 1028 electrons per cubic metre. Find the magnitude of:
i. The current density ii. The drift velocity

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6 months 2021-07-18T05:15:13+00:00 1 Answers 61 views 0

The current density is

The drift velocity is

Explanation:

From the question we are told that

The nominal diameter of the wire is

The current carried by the wire is

The power rating of the lamp is

The density of electron is

The current density is mathematically represented as

Where A is the area which is mathematically evaluated as

Substituting values

So

The drift velocity is mathematically represented as

Where e is the charge on one electron which has a value

So