Question

A straight, vertical wire carries a current of 1.25 Adownward in a region between the poles of a large superconducting electromagnet, where the magnetic field has a magnitude of B = 0.560 Tand is horizontal.

Part A

What is the magnitude of the magnetic force on a section of the wire with a length of 1.00 cm that is in this uniform magnetic field, if the magnetic field direction is east?

B

What is the direction of the magnetic force on a section of the wire with a length of 1.00  that is in this uniform magnetic field, if the magnetic field direction is east?

	south
	north
	west
	east

Part C

What is the magnitude of the magnetic force on a section of the wire with a length of 1.00 cm that is in this uniform magnetic field, if the magnetic field direction is south?

D

What is the direction of the magnetic force on a section of the wire with a length of 1.00 cm that is in this uniform magnetic field, if the magnetic field direction is south?

Part E

What is the magnitude of the magnetic force on a section of the wire with a length of 1.00 cm that is in this uniform magnetic field, if the magnetic field direction is30.0 ∘ south of west?

Part F

What angle will the magnetic force on this segment of wire make relative to the north, if the magnetic field direction is 30.0 ∘ south of west?

Answer 1

Current = I = 1.25 A ( downward )

Magnetic field = B = 0.560 T ( horizontal)

Wire length = L = 1.00 cm =0.01 m

Angle between wire length and magnetic field = = 90 degree

Magnitude of the magnetic force = F = BIL sin

F _mag=0.560*1.25*0.01*sin 90

Magnitude of the magnetic force=F_mag =0.007 N=7mN

So we found the force now. Understand the figure which I gave first. In that figure the magnetc field B and force F are kept in a 90⁰ differece. So the magnetic field direction is east, then the force direction is 90⁰ of that of magnetic field.

So it will be in the south direction. We need to look clockwise direction. 90⁰ clockwise of east is south. So the direction of force will be along south if B is in east direction.

Next the magnetic field direction is assumed along south. So 90⁰ clockwise direction of south is along the west direction. The magnitude of the force is same only 7mN. But the direction will be along the west direction.

Next B is kept at 30⁰ south of west. So 90⁰+30⁰ will be at the west of north quadrent. The value of force wont change. Why? Because we need to consider only the angle between the magnetic force and magnetic field. They are at 90⁰ difference always. So the magnitude will be same always.