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Can you please help me with a question about AS Electricity and Circuits?

The question is:

An electric light is 3m away from the switch. It is connected to the switch by copper wire of cross sectional area 0.50mm^2. The carrier density for copper is 8.5 x 10^28 m^-3, and the electron charge is 1.6 x 10^-19 C. [5]

a) If the light takes a current of 0.25A, show that an electron in the wire near the switch will take almost a day to reach the lamp.

I know the equations Q=IT (where Q is the total amount of charge, I is the current and T is the time taken) and I=nAVq.

How do I answer this question? Can someone please walk me through it so I know how to answer it? (It's 5 marks so I guess it's multiple stages)

Any help would be amazing and greatly appreciated, I ideally want to do it tonight so I would like help asap please!

Thanks

Reply 1

Joinedup

Original post by blobbybill

Well you have been given values for I,n,q,A and the question is asking something that could be answered if you knew V.

so you need to algebraically manipulate I=nAVq until you get V on it's own on one side of the equals sign and then find V