Question

Question #c11d1

Answer 1

See below.

Explanation:

Ac generator works on the principle of Electromagnetic induction .

consider the following Image .we know according to lenz law
`Vprop(dphi_b)/dt`

hence there must be change in magnetic field in order to crate potential so , initially the loop is given a small torque as the arrow shown in the figure .

as the loop rotates in the magnetic field the force on the branch AB is shown by .

here the Force `vecF` is the force on electrons and hence the direction of motion of electrons in magnetic field . Now the electrons move from D to C to B to A but current moves in opposite direction which is A to B to C to D .

But wait , we have to see that in AC generator there are slip rings due to which when the loop completes one cycle it the direction of current changes , for instance .

in above figure if we start with `90^o` and go till `270^o` till that time A is negative and D is positive , but from `270^o` to `0^o` A becomes positive for that interval and D is negative for that interval .

In this way In one complete cycle it produces the AC current by different polarity of Terminal A and B .