Do as many problems and you can. There is only a limited number of questions they can ask you and if you have done a question similar to the one they give then you would know how to do it.
So do as many past papers as you can, if you need more or don't have any then see here...
Dreamerish is right. You fill the burette with the solution of known concentration. I think this is done so you can measure how much of the known solution is needed to change colour.
A current carrying conductor experiences a force in an external magnetic field.
or
The motor effect is the action of a force experienced by a current carying conductor in an external magnetic field.
Both are the same thing.
Because the two conductors experience a force away from the rotor and the resultant force is 0 because they both cancel each other out. The momentum and the change in direction of the current keeps it going when it reaches this point.
Sorry for the confusion, fixed now.
I've been searching for ages but can't seem to find any good information on China's financial market.
Does anyone have links or information about China's financial markets?
Thanks