Exam 14: Magnets and Electromagnetism

A transformer has 200 turns on the primary and 20 turns on the secondary. The primary is connected to a direct current source of 100 millivolts. The voltage in the secondary coil will be

The magnetic pole near the Earth's north geographic pole actually has to be

Imagine that this classroom contains a constant magnetic field that points from the front to the back. In front of you a negative charge is slowly moving horizontally to your left. As you watch, the magnetic force on the charge

A horizontally moving positive sodium ion enters a magnetic field that points up. The magnetic force pushes the charge out of its original path. When viewed as shown on this page, what direction will the magnetic force point?

A long straight wire carries a current. A positive charge moves toward the wire in a direction perpendicular to the wire. The direction of the force on the charge will be

A horizontal straight wire carries a current from east to west. The resulting magnetic field lines are

A bar magnet is held near a single closed loop of wire. The magnet is aligned with the loop axis, and the north pole is facing the loop. If the magnet is moved away, the current induced in the loop will be in a ______________ direction as viewed from the side the magnet is on.

If a current of negative charge flows in a circle in the direction of one's curled fingers of the right hand, the resulting magnetic field would be in the direction

In the southern hemisphere, the north pole of a compass needle

Electrons flow around a circular wire loop in a horizontal plane, in a direction that is clockwise when viewed from above. This causes a magnetic field. Inside the loop, the direction of this field is

A step-up transformer that doubles the input voltage is designed to work with an input voltage that varies at 60 Hz. The frequency with which the output voltage varies is ____________ Hz.

The north pole of a bar magnet is moved away from a single closed loop of wire along the axis of the loop. The induced current in the loop produces an effective ____________ pole toward the bar magnet.

You see a positively charged helium ion in space, and it is at rest with respect to your spacecraft. Since you are studying for the final exam, you decide to experiment. You slowly push the N pole of a bar magnet closer to the helium ion. What happens to the helium ion?