Exam 29: Magnetic Fields Due to Currents

Two long straight wires enter a room through a window.One carries a current of 3.0 A into the room while the other carries a current of 5.0 A out.The magnitude of the path integral around the window frame is:

A long straight wire carrying a 3.0 A current enters a room through a window 1.5 m high and 1.0 m wide.The path integral around the window frame has the value:

Electrons are going around a circle in a counterclockwise direction as shown.At the center of the circle they produce a magnetic field that is:

If the magnetic field is uniform over the area bounded by a circle with a radius R, the net current through the circle is:

Two long straight wires are parallel and carry current in the same direction.The currents are 8.0 and 12 A and the wires are separated by 0.40 cm.The magnetic field at a point midway between the wires is:

In Ampere's law, the symbol is:

In the figure, if the current element has a length of 1.0 mm, carries a current of 2.5 A, and is a distance of 4.8 cm from the point P, what is the magnitude of the magnetic field at point P?

Two parallel wires carrying equal currents of 10 A attract each other with a force of 1 mN.If both currents are doubled, the force of attraction will be: