Exam 15: Electromagnetism

In a ______________, motion must be supplied so that the flux and conductor can cut across each other to induce voltage across the ends of the conductor.

For a coil, the induced voltage is increased by

The movable arm of an electromechanical relay is called the ______________.

What is often used to show how much flux density results from increasing the amount of field intensity?

A B-H curve is often used to show how much flux density results from increasing the amount of field intensity.

What generally causes a relay to chatter?

When magnetic flux moves, the motion of magnetic lines cutting across a conductor forces free electrons in the conductor to move and produce current by an action called

For an electromagnet, the strength and intensity of the magnetic field does not depend on current flow or number of coil turns in a given length.

Reducing the residual induction is a method of demagnetization called gaussing.

An electromechanical device that operates switching contacts by electromagnetic induction is a

Which of the following does not help to determine the amount of induced voltage?

The cgs unit for field intensity is the gilbert.

When the magnetic lines of two fields are in the same direction, the lines of force aid each other, making the field stronger.

The SI abbreviation for ampere-turn is

The cgs unit of magnetomotive force is the

The effect of little change in flux density when the field intensity increases is called

A coil of wire with only one turn is generally called a solenoid.

The minimum amount of relay coil voltage necessary to energize or operate a relay is called

A coil of wire conductor with more than one turn is generally called a(n)

The magnetomotive force of a coil is ______________ proportional to both the current and the number of turns.