Exam 22: Magnetic Forces and Magnetic Fields

Two very long parallel wires carry currents in the positive x direction.One wire (current = 15 A)is coincident with the x axis.The other wire (current = 50 A)passes through the point (0,4.0 mm,0).What is the magnitude of the magnetic field at the point (0,0,3.0 mm)?

A long straight wire (diameter = 2.0 mm)carries a current of 30 A.What is the magnitude of the magnetic field 2.5 mm from the axis of the wire?

The figure shows a cross section of three parallel wires each carrying a current of 24 A.The currents in wires B and C are out of the paper,while that in wire A is into the paper.If the distance R = 5.0 mm,what is the magnitude of the force on a 4.0-m length of wire A?

Equal currents of magnitude I travel into the page in wire M and out of the page in wire N.Eight directions are indicated by letters A through H. The direction of the magnetic field at point P is

A segment of wire of total length 3.0 m carries a 15-A current and is formed into a semicircle.Determine the magnitude of the magnetic field at the center of the circle along which the wire is placed.

The figure shows a cross section of three parallel wires each carrying a current of 5.0 A out of the paper.If the distance R = 6.0 mm,what is the magnitude of the magnetic force on a 2.0-m length of any one of the wires?

The segment of wire (total length including portions of incoming and outgoing wire = 6R)is formed into the shape shown and carries a current I.What is the magnitude of the resulting magnetic field at the point P?

One long wire carries a current of 30 A along the entire x axis.A second long wire carries a current of 40 A perpendicular to the xy plane and passes through the point (0,4,0)m.What is the magnitude of the resulting magnetic field at the point y = 2.0 m on the y axis?

What is the magnitude of the magnetic field at point P if a = R and b = 2R?

If a = 1.0 cm,b = 3.0 cm,and I = 30 A,what is the magnitude of the magnetic field at point P?

Two long parallel wires separated by 5.0 mm each carry a current of 60 A.These two currents are oppositely directed.What is the magnitude of the magnetic field at a point that is between the two wires and 2.0 mm from one of the two wires?

One reason why we know that magnetic fields are not the same as electric fields is because the force exerted on a charge +q

Two long parallel wires carry unequal currents in the same direction.The ratio of the currents is 3 to 1.The magnitude of the magnetic field at a point in the plane of the wires and 10 cm from each wire is 4.0 $\mu$ T.What is the larger of the two currents?

An explorer walks into a lab in a science building.She has a compass in her hand and finds that the south pole of her compass points toward the room's East wall when she is nearer that wall and toward the west wall when she is nearer that wall.You could explain this if magnetized metal had been installed in the East and West walls with North poles pointing into the room.If no magnetic material was installed in the North or South walls of the room,she would expect that

What is the kinetic energy of an electron that passes undeviated through perpendicular electric and magnetic fields if E = 4.0 kV/m and B = 8.0 mT?

A thin infinitely large current sheet lies in the y-z plane.Current of magnitude J_s per unit length along the z axis travels in the y-axis direction,which is up out of the page.Which diagram below correctly represents the direction of the magnetic field on either side of the sheet?

A particle (q = -4.0 $\mu$ C,m = 5.0 mg)moves in a uniform magnetic field with a velocity having a magnitude of 2.0 km/s and a direction that is 50 $\degree$ away from that of the magnetic field.The particle is observed to have an acceleration with a magnitude of 5.8 m/s².What is the magnitude of the magnetic field?