Magnetism AP Free Response Problem, HELP

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Homework Statement

teacherweb.com/CT/TrumbullHS/.../APOralFinalQuestions1-10.doc for pic.

The magnitude of the magnetic field in teslas at a distance d from a long straight wire carrying a current I is given by the relation B = 2 X 10-7 I/d. The two long straight wires shown above are perpendicular, insulated from each other, and small enough so that they may be considered to be in the same plane. The wires are not free to move. Point P, in the same plane as the wires, is 0.5 meter from the wire carrying a current of 1 ampere and is 1.0 meter from the wire carrying a current of 3 amperes.

a. What is the direction of the net magnetic field at P due to the currents?

b. Determine the magnitude of the net magnetic field at P due to the currents.
A charged particle at point P that is instantaneously moving with a velocity of 106 meters per second toward the top of the page experiences a force of 10-7 Newtons to the left due to the two currents.

c. State whether the charge on the particle is positive or negative.

d. Determine the magnitude of the charge on the particle.

e. Determine the magnitude and direction of an electric field also at point P that would make the net force on this moving charge equal to zero.

Homework Equations

B = mu not * current / 2 pi r

F = B I L

The Attempt at a Solution

For part b) i found the net magnetic field as 2.0 times 10 ^ 7, is this right? and I don't know how to do anything elsee! please help

 

[anathema]

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I would like to clarify and offer assistance in solving the given problem. Firstly, the equation B = 2 x 10^-7 I/d is the correct formula for calculating the magnitude of the magnetic field at a distance d from a long straight wire carrying a current I. However, the formula B = mu not * current / 2 pi r is also valid, where mu not is the permeability of free space and r is the distance from the wire.

To solve the problem, we first need to determine the direction of the net magnetic field at point P. Since the two wires are perpendicular to each other, the magnetic fields generated by each wire will be perpendicular as well. Therefore, the net magnetic field at point P will be in the direction of the vector sum of the two individual magnetic fields, which can be determined using the right-hand rule.

Next, we can calculate the magnitude of the net magnetic field at point P by plugging in the given values into the formula B = 2 x 10^-7 I/d. This will give us the magnitude of the magnetic field due to each wire, which we can then add together to get the net magnetic field.

Moving on to part c, we can determine the charge on the particle by using the formula F = BIL, where F is the force experienced by the particle, B is the net magnetic field at point P, and L is the length of the wire. We know the value of F and B, and we can assume a value for L (since it is not given in the problem), which will allow us to solve for the current I. Once we have the value of I, we can use the formula Q = I x t, where Q is the charge, I is the current, and t is the time for which the particle is moving with a velocity of 10^6 m/s.

Lastly, to determine the electric field at point P that would make the net force on the particle equal to zero, we can use the formula F = Q * E, where F is the force experienced by the particle, Q is the charge on the particle, and E is the electric field. We know the value of F and Q, so we can solve for E.

I hope this helps in solving the problem. Do let me know if you need any further clarification or assistance. Good luck!