Studied by 5 people

0.0(0)

Get a hint

Hint

Electromagnetism includes the study of electricity, magnetism, and how they are connected.

1

Magnetic Field

The space surrounding a magnet is called a magnetic field.

New cards

2

Notation of magnetic field

We use (x) when the magnetic field goes into the plane.

We use (.) when the magnetic field goes out of the plane.

New cards

3

Bar Magnet

A permanent bar magnet creates a magnetic field that closely resembles the magnetic field produced by a circular loop of current-carrying wire.

New cards

4

Magnetic Force

*F = qv x B*

with magnitude:

*F = qv B sin theta*

F = force

q = charge

v = velocity

B = magnetic field

New cards

5

Right-Hand Rule

Whenever you use the right-hand rule, follow these steps:

Orient your hand so that your thumb points in the direction of the velocity v. If the charge is negative, turn your thumb by 180 degrees.

Point your fingers in the direction of B.

The direction of FB will then be perpendicular to your palm.

New cards

6

Magnetic force on a current carrying wire

*F = ILB*

with magnitude:

*F = BIL sin theta*

F = force

B = magnetic field

I = current

L = length of conductor

New cards

7

Magnetic field created by current-carrying wire

*B= μo I / 2πr*

B = magnetic field

I = applied current

μo = permeability of free space

r = the distance from the wire where the magnetic field is calculated

New cards

8

Lenz’s Law

The induced current will always flow in the direction that opposes the change in magnetic flux that produced it.

**Emf = -N (ΔΦ/ Δt)**

‘Emf’ = Induced voltage or electromotive force.

‘N’ = The number of loops.

‘Δϕ’ = Change within magnetic flux.

‘Δt’ = Change in time

New cards

9

Faraday’s Law of electromagnetic induction

Whenever a conductor is placed in a varying magnetic field, an electromotive force is induced. If the conductor circuit is closed, a current is induced, which is called induced current.

The induced emf in a coil is equal to the rate of change of flux linkage.

*emf = − dΦ/ dt*emf = electromotive force

dΦ = change in magnetic flux

dt = change in time

New cards

10

Induced current

It is created in three ways:

Changing the area of the loop of wire in a stationary magnetic field.

Changing the magnetic field strength through a stationary circuit.

Changing the angle between the magnetic field and the wire loop.

New cards

11

Motional Emf

Motional emf is the electromotive force generated by the motion of a conductor through a magnetic field.

It is given by the equation

, where B is the magnetic field strength, l is the length of the conductor, and v is the velocity of the conductor.*emf = Blv*This phenomenon is used in various applications, such as electric generators and motors.

New cards

12

Solenoid

Solenoid is a device that is constructed by a series of coaxial wires through which a continuous current flow.

New cards

13

When a change of current in one circuit induced a voltage into another circuit, this process is known as:

mutual induction

New cards

14

Increasing the current through a conductor will cause the magnetic field around the conductor to:

increase in strength

New cards

15

Current flow in a conductor produces:

a magnetic field

New cards

16

Whenever there is motion between a conductor and a magnetic field:

a voltage is generated in that conductor

New cards

17

What is a magnetic material?

Any material that is attracted to a magnet and has magnetic domains.

New cards

18

What is a magnetic pole?

A place on the magnet where the force of attraction is greatest.

New cards

19

Describes it to behaviors of magnetic poles when they are placed next to each other.

a) like poles repel each other

b) unlike poles attract each other

New cards

20

In what direction do the imaginary magnetic lines of force of a closed loop flow?

From the north pole to the south pole.

New cards

21

electromagnet

Device that uses current flow through conductors around a core to create magnetism.

New cards

22

flux

The total lines of force surrounding a magnetic material. The symbol is Φ.

New cards

23

permeability

The ability of a material to concentrate flux as compared to air. The symbol is μ.

New cards

24

What three factors affect the strength of the magnetic field around the coil?

a) The amount of current through the coil

b) The number of turns on the coil

c) The core material

New cards

25

State the three factors that determine them amount of induced emf.

a) flux density

b) the number of turns in a conductor

c) The rate at which lines of force are cut by the conductor which is determined by the velocity and the angle of cut

New cards

26

mutual induction

Mutual induction takes place when a change in current and one circuit causes a voltage to be induced into another separate circuit.

New cards

27

State two applications that use the principle of mutual induction.

a) ignition coils

b) transformers

New cards

28

Inductance is symbolized by __ and is measured in __, symbol __.

L, henry, H

New cards