current in a generator

[moekamo]

for the attached question i dont get how to do it.

If i use the right hand slap rule with field going left to right, current from A to B, i get a force pushing down on the loop so it spins anti clockwise.

But this is the answer:

Answer: Clockwise.

Explanation:
Consider a positive charge at A. If the turbine spins clockwise, at the instant shown, the positive
charge will be rising. The RH slap rule shows that the charge will be pushed (by an induced force)
from A to B as required. (Note: The pushing of the charge is the induced current)

Which way is the correct way to use

[IntoTheNewWorld]

The problem with your method is this is a generator not a motor =]

[almostatrap]

You need to use lenz's law.

Induced current in a loop will be in the direction so that the magnetic flux it creates will oppose the change in the flux that produced it.

As the loop rotates from the position shown to the vertical position (clockwise), the magnetic flux from north to south through the loop increases.

So the induced current must create a flux from south to north to oppose this, and right hand grip rule indicates the current goes from A to B.


You kind of have to apply this backwards.


or much simpler: Induced current in a conductor create a force that will oppose the relative motion.  A to B creates an anticlockwise force, so the motion is clockwise.