this is a question my astronomy professor gave us, but i can't find the answer in my $100 book.?

Question

A toy top is spinning on a table. If the charge on it is negative and it is spinning clockwise as seen from the top, in which direction is the magnetic field (up or down), and why?

Answer 1

The CORRECT answer is up. If it is spinning clockwise and has a NEGATIVE charge on it, then by convention we pretend that it is a positive charge moving in the opposite direction (counterclockwise). Use THAT information and then apply the right-hand rule. With your fingers pointing in a counterclockwise direction, your thumb points up, which is the direction in which the magnetic field will be pointing.

Answer 2

Can you first find the direction of the current? Remember that negative charge will reverse the direction of the current (which is why a previousl answer is wrong). This will tell you the direction of the magnetic field using the right hand rule. Also, the location where you are measuring the magnetic field should be given since it will change directions if you get far enough away from the top.

Answer 3

Using the right-hand rule, a clockwise spin gives a "down" orientation.

Answer 4

The answer is up. But it's a bit complicated t o explain--though tlbs-101 is right --you use the "right-hand rule." But you won't find it in an astronomy textbook-because its a physics question--that's where you need to look.

Answer 5

Up.

Right hand rule... negative charges moving clockwise... simple.

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Answer 6

If he told you it was in the book, it will be in the book.
The price of the book doesn't mean anything. I pay a little over $800 for all my books and it doesn't mean they are the best on the market.

Answer 7

Fleming's right hand rule

Here is your answer>
http://en.wikipedia.org/wiki/Fleming%27s_right_hand_rule

Answer 8

you are ALL wrong.....
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... its left! =)