Exam 30: Sources of the Magnetic Field

Two solenoids are each made of 2 000 turns of copper wire per meter.Solenoid I is 2 m long,while solenoid II is 1 m long.When equal currents are present in the two solenoids,the ratio of the magnetic field B_I along the axis of solenoid I to the magnetic field B_II along the axis of solenoid II,B_I/B_II,is

A long straight wire (diameter = 2.0 mm)carries a current of 40 A.What is the magnitude of the magnetic field 1.5 mm from the axis of the wire?

A long wire carries a current of 3.0 A along the axis of a long solenoid (radius = 3.0 cm,n = 900 turns/m,current = 30 mA).What is the magnitude of the magnetic field at a point 2.0 cm from the axis of the solenoid? Neglect any end effects.

At a point in space where the magnetic field is measured,the magnetic field produced by a current element

Two long parallel wires lie in the xz plane.One wire passes through the point (−2 m,0,0)and the other through the point (+2 m,0,0).The wires carry equal currents in the positive z direction.

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

Two long parallel wires separated by 4.0 mm each carry a current of 24 A.These two currents are in the same direction.What is the magnitude of the magnetic field at a point that is between the two wires and 1.0 mm from one of the two wires?

Two long straight parallel wires separated by a distance of 20 cm carry currents of 30 A and 40 A in opposite directions.What is the magnitude of the resulting magnetic field at a point that is 15 cm from the wire carrying the 30-A current and 25 cm from the other wire?

What is the magnitude of the magnetic field at point P in the figure if a = 2.0 cm,b = 4.5 cm,and I = 5.0 A?

A solenoid consists of 100 circular turns of copper wire.Parts of three turns,A,B and C,are shown below. When a current flows through the coil,

A single circular (radius = R)loop of wire is located in the yz plane with its center at the origin.The loop has a clockwise current as seen from the point (+R,0,0).The direction of the magnetic field at the point

When a microwave filter consisting of vertical parallel metal rods is in the absorbing position,oscillating currents are set up in the rods.At any one instant,the current in each rod has the same magnitude and direction.At that instant

Three long,straight,parallel wires each carry a current of 10 A in the positive x direction.If the distance between each wire and the other two is 10 cm,what is the magnitude of the magnetic force on a 20-cm length of either of the wires?

A segment of wire of total length 2.0 m is formed into a circular loop having 5.0 turns.If the wire carries a 1.2-A current,determine the magnitude of the magnetic field at the center of the loop.

A long solenoid (diameter = 5.0 cm)is wound with 960 turns per meter of thin wire through which a current of 300 mA is maintained.A wire carrying 12 A is inserted along the axis of the solenoid.What is the magnitude of the magnetic field at a point 2.0 cm from the axis?

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?

The field at (0,1.0 m,0)is in the negative y direction.

A conducting rod with a square cross section (3.0 cm × 3.0 cm)carries a current of 60 A that is uniformly distributed across the cross section.What is the magnitude of the (line)integral Around a square path (1.5 cm × 1.5 cm)if the path is centered on the center of the rod and lies in a plane perpendicular to the axis of the rod?

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.

A toroid is made of 2 000 turns of wire of radius 2.00 cm formed into a donut shape of inner radius 10.0 cm and outer radius 14.0 cm.When a 30.0-A current is present in the toroid,the magnetic field at a distance of 11.0 cm from the center of the toroid is