Simple multiple choice question about conventional current

[scilearner]

Hello everyone,

 

I got a question

 

Electrons moving through a resistor experience a force if the resistor is in a magnetic field. A resistor is oriented east west as shown with the earth's magnetic field into the page

 

 

-----------XXXXXX-----------> (Direction of current given)

 

 

 

X- Magnetic field into the page

 

An electron travelling through the resistor will experience a force due to the magnetic field which is

 

A Up

B Down

C into the page

D out of the page

 

Ok the answer that is stated is A. Yeah I know you can get this by using the simple right hand palm rule. My problem is I thought electron move in the opposite direction to the conventional current. So don't we have to take current as left and the answer is B. Also bit off topic why is that in an electron charge we take the direction of current as the opposite to the given current. Is it for the same reason I just said above. So isn't this a question like electron charge. Any help would be appreciated. Thanks

Edited July 29, 2008 by scilearner

[insane_alien]

all i can say about conventional current is: stupid US idiots.

 

even after it was discovered that negativly charged electrons were the charge carriers they decided to keep the conventions from when they thought it was a positively charged charge carrier.

 

while this is fine for most electronic circuits, it gets downright confusing for when you want to see what actually happens.

[DrP]

Use the 'left hand rule'... http://en.wikipedia.org/wiki/Left-hand_rule

 

Index finger is filed / middle finger is current / thumb is force experienced.

 

You should be able to get the answer easily from this..

[Klaynos]

Do what DrP says.

 

For the left hand rule you use conventional current, which means if you're dealing with just electrons not in a wire, you have to point in the opposite direction to that which the electron moves.

[scilearner]

Thanks everyone who helped . Yes understand now this is a case where the electrons are inside the wire so we have to use conventional current. Yeah I agree with the conventional current. I don't like it too much.

 

Thanks again everyone who helped

[Externet]

all i can say about conventional current is: stupid US idiots.

 

----Ovation ! ----