Magnetic forces on current-carrying wires

[hooman]

See the attached file on the above post..

i've already seen it but i don't understand. can you please explain it to me based on the question i asked above.

 

[Doc Al]

How about answering the question I posed earlier?

So what additional force must wire Z exert on X to produce the given resultant?

You are given the resultant F/L on wire X. You've calculated the contribution from wire Y. So, what must be the contribution from wire Z? That will tell you the direction of the current in Z and allow you to calculate the magnitude of that current.

 

[hooman]

How about answering the question I posed earlier?

You are given the resultant F/L on wire X. You've calculated the contribution from wire Y. So, what must be the contribution from wire Z? That will tell you the direction of the current in Z and allow you to calculate the magnitude of that current.

2.5x10^-4 . is it right?

 

[MartinCarr]

Did you work this out or do you need me to explain more?

 

[Doc Al]

2.5x10^-4 . is it right?

Don't just give a numeric answer. Describe how you got your answer. And what does that tell you about the direction and magnitude of the current through Z?

 

[hooman]

Did you work this out or do you need me to explain more?

explain please

 

[hooman]

Don't just give a numeric answer. Describe how you got your answer. And what does that tell you about the direction and magnitude of the current through Z?

from the question a, i need to know the direction whether it is right or wrong. so, fron the diagram itself we can know whether it is right or wrong. but i don't know how. i cannot determine the direction by using calculation because how can i know the equation have to use minus or addition.

 

[hooman]

Did you work this out or do you need me to explain more?

the statement is wrong. the right one is the resultant force per unit length is actually acted on Y not on X. it's a mistake in typing the question. sorry. so how to determine the direction whether it's right or wrong?

 

[hooman]

Don't just give a numeric answer. Describe how you got your answer. And what does that tell you about the direction and magnitude of the current through Z?

the statement is wrong. the right one is the resultant force per unit length is actually acted on Y not on X. it's a mistake in typing the question. sorry. so how to determine the direction whether it's right or wrong?

 

[Doc Al]

the statement is wrong. the right one is the resultant force per unit length is actually acted on Y not on X. it's a mistake in typing the question.

At least that explains the "towards X" statement.

so how to determine the direction whether it's right or wrong?

Do you know how to find the force/length between two current-carrying wires? Start there.

Try this: Magnetic Force Between Wires

 

[hooman]

At least that explains the "towards X" statement.

Do you know how to find the force/length between two current-carrying wires? Start there.

Try this: Magnetic Force Between Wires

what does it means by pointing towards X? yes, I do know how to find F/l

 

[hooman]

At least that explains the "towards X" statement.

Do you know how to find the force/length between two current-carrying wires? Start there.

Try this: Magnetic Force Between Wires

but, in the question in the link that you gave, i don't know how to do it because the question itself doesn't give any value

 

[MartinCarr]

As we know a current carrying wire will induce a magnetic field around it. This field will be clockwise around the wire in the direction of current. Both wire Y and Z will exert a force on X.

By looking at the direction of the magnetic field from Y and then Z at the side of X (either into or out of the paper) you can use the hand rules (movement, flux & current) you can work out which way the wire will move.

Using the formula in the attachment you can then calculate the force and hence the direction and value of current in the question.

 

[Neelima]

Considering the figure as it is ,
Force on X due to Y is towards left
Force on X due to Z is towards right.
As net force on X is towards left ( see the attachment ).
F(y) > F (z).
F (net) = F(y) - F( z)
50 x 10^(-5) = 25 x 10^ (-5) - (20xI /6) x 10^(-5)
Solving we get negative value for I which is meaningless . In my opinion it should not be.
So direction of current in Z should be downward.
Then due to both Y and Z forces will be towards X.