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# Unit 2 electricity q watch

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1. Could someone pls help me out?
In this mcq could someone explain to me how we got the ratio of the drift speeds? I know it's from the I = navq formula but how? TT
2. I would rearrange so I can see more clearly what the drift speed depends on

v = I/naq

The n and q don't change so essentially we have v α I/a. The thing to watch is that if A has twice the diameter of B, then it has area a 4x as big.

Does that help? Look for a row in the table which would fit the v α I/a relationship.
3. That clears things up a bit. Thank you =D I just don't understand one thing though. How would the area of A be 4 times as big as area of B? Why not twice?
4. Yikes, and having read it properly this time, if they're in series, the current must be the same in both, so that knocks out C and D and gives you a 50/50 chance of guessing

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Updated: February 14, 2018
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