In an AC (alternating current) generator, a coil of wire rotates in a magnetic field.
Which of the following would change the potential difference measured by the voltmeter in the system above?
A. 3 only
B. 1, 2 and 3
C. 1 and 2 only
D. 2 only
E. 1 and 3 only
Let us review each statement:
By having more and more loops of turns of the wire, the crests and troughs overlap the flux line at a faster rate or increasing the amount of times they cut through the magnetic field, and therefore the induced e.m.f will increase. This statement is therefore, correct.
The diameter or thickness of the wire could have an effect on it’s resistance on the current- but it has no relation to the induced potential difference in this system. Therefore, this answer is incorrect.
If the same coil of wire passed through the magnetic field, but it’s velocity or speed increases, the wires will cut the flux lines at a faster rate, therefore the induced e.m.f produced would also increase. Hence making this statement correct.
Our final answer will now be, considereing statements 1 and 3 are correct, E.
Doesn’t the increased thickness of wire increase resistance? If so, that would cause the voltage to drop, no?
Hi Karam,
So- no, in short. The thinner a wire is, the greater resistance it has; this is because a thinner wire has fewer electrons to carry an electric current. Using a thicker wire reduces resistance- it might be confusing but a good review of electricity and circuits will do you good.
Hope this helps.
Best,
Ahd
Hi.
In the explanation above you said that thicker wires increase the potential difference by reducing the resistance.
But why does the answer say this view is wrong?
I don’t know which part is wrong.
Please distinguish the differences in my answers between current and emf.