Electromag

Increase according to the inverse-square law

Two identical positive charges are brought closer together. The electrostatic force between them will

Force per unit positive test charge

The electric field at a point is defined as the

Electric field is strongest

Electric field lines are closest together where the

Work done per unit charge

Electric potential is best described as

Perpendicular to electric field lines

Equipotential surfaces are always

Geometric symmetry

Gauss’s Law is most useful when the charge distribution possesses

Cylinder

Which Gaussian surface is most appropriate for an infinitely long charged wire?

Decrease capacitance

Increasing the plate separation of a parallel-plate capacitor will

Electric field

Inserting a dielectric between capacitor plates generally

Circular

Magnetic field lines around a straight conductor carrying current are

Magnetic flux linking a conductor changes

Faraday’s Law states that an induced emf is produced whenever

Opposes the change in magnetic flux

Lenz’s Law states that the induced current

Mutual induction

A transformer operates based primarily on

Current

An inductor opposes changes in

Magnetic field

The energy stored in an inductor is stored in the

A conductor’s own changing current

Self-inductance is caused by

Perpendicular electric and magnetic field

Electromagnetic waves consist of

High permeability and low hysteresis loss

Why is soft iron commonly used as a transformer core?

Hard steel

Which material is best suited for permanent magnets?

Produce unwanted heating losses

Eddy currents are generally undesirable because they

Eddy current loss

Laminating transformer cores primarily reduces

Repeated magnetization and demagnetization of the core

Hysteresis loss is mainly caused by

Air cannot be magnetized like ferromagnetic materials.

Which statement best explains why air-core inductors do not suffer hysteresis loss?

Electricity and magnetism

Maxwell’s equations unified the theories of

A magnetic field

According to Maxwell, a changing electric field produces

DC does not produce a changing magnetic flux after the initial transient.

Why does a transformer not operate with a pure DC supply?

Electric current

Which quantity is directly responsible for producing magnetic fields around a conductor?

It determines how easily magnetic flux is established.

Why is permeability an important property of magnetic materials?

A stationary charge produces only an electric field.

Which statement about electric and magnetic fields is TRUE?

Electric currents produce magnetic fields, and changing magnetic fields can produce electric fields.

Which statement best summarizes the relationship between electricity and magnetism?