Solenoids (75-78)

In order for a wire to feel a magnetic force what must be true?

It must have an electric current going through it.

What types of particles can be deflected by a magnetic force?

Moving charged particles

A current carrying wire creates which types of fields?

ELectric and magnetic field

What law is roughly analogous to Gauss’s law for magnetic fields?

AMpere’s law

Whom is ampere’s law named for?

Andre-Marie AMpere

The units for current are named after who?

Andre-Marie AMpere

What country is Andre-Marie AMpere from?

France

What are the units for current?

Amperes (amps)

What is drawn to determine what the magnetic field around an object looks like when using AMpere’s law?

Amperian loops

What is observed when using Ampere’s law?

How the magnetic field changes (if at all) Along the loops

When would integral calculus have to be used when calculating magnetic fields with AMpere’s law?

When the magnetic field isn’t constant

What is the expression for a magnetic field with Ampere’s law?

B= µI/2πr

What does 2(pi)r represent in Amperes law?

The length around the loop (circumference)

What is the relationship between the magnetic field and the distance away from a wire?

The magnetic field varies inversely with distance

What is the symbol for permeability of free space?

µ

What is a solenoid?

Multiple circular loops on top of each other

What is the magnetic field of a solenoid?

Like the magnetic field of a bar magnet; It forms coinciding loops around itself

What is AMpere’s law for a solenoid?

B= µI(N/L)

What does L represent in the expression for the magnetic field of a solenoid?

The length of the solenod

What does N represent in Ampere’s law for a solenoid?

The number of loops

What is the relationship between position and the magnetic field of a solenoid?

Independent of position

What does the relationship between the magnetic field and the radius in Ampere’s law for a current carrying were imply about the relationship between the magnetic field and position?

That the magnetic field for a current carruing wire is NOT independent of position

The magnetic field of a solenoid is constant as long as what the position being analyzed is what?

INside the solenoid

What does the magnetic field in a solenoid depend on?

The physical properties of the object

What is the relationship between the magnetic field of a solenoid and its length?

Inverse relationship

What are miniature solenoids used for?

Electric circuits

What is a larger scale example of a solenoid?

The tube in an MRI machine

The currents in an MRI machine are so high they can produce a magnetic field in what range?

1-2 Tesla

What happens to metal objects in the vicinity of an MRI machine?

They become deadly projectiles when the machine is in operation