I eliminated A but I am unable to eliminate either of the other options to arrive conclusively at the answer : C
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P.D. between two points in a wire is.... watch
- Thread Starter
- 31-03-2011 12:43
- 31-03-2011 14:32
I reckon it would be C .
Units of Power is in Watts or V A since P=IV
C mentions the Ratio of power to Current .
I just looked at the units and concluded that V A : A would just give V ( as the Amps symbols would cancel out), which is the unit for the potiential difference across the wire.
- 31-03-2011 14:33
We know that an expression for the power generated in the wire is P = VI. So rearranging, we get V = P/I, which means it roughly needs to have the dimensions of joules/coulomb.
If you take the ratio of energy/current or power/charge, you don't get the same thing as before.