finals physics 2

magnetic field

a vector field that

describes the magnetic influence on

moving electric charges, electric

currents, and magnetic materials.

Right-Hand Rule No. 1

To find the direction of the force on a positive charge,

point your fingers in the direction of velocity (v), curl them toward the magnetic

field (B), and your thumb points in the direction of the force (FB

). For a negative

charge, the force is in the opposite direction.

Magnetic flux

is a measure of the total magnetic field which

passes through a given area. It is a useful tool for quantifying the

effects of the magnetic force on something occupying a given area.

Ferromagnetic Materials

Exhibit

strong attraction to magnetic fields

and can retain their magnetic

properties after the external field is

removed (e.g., Iron, Nickel, Cobalt).

Paramagnetic Materials

Have a

weak, positive susceptibility to

magnetic fields. They are slightly

attracted by a magnetic field and do

not retain magnetic properties when

the field is removed (e.g., Aluminum,

Platinum).

Diamagnetic Materials

Have a weak,

negative susceptibility to magnetic fields.

They are slightly repelled by a magnetic field

(e.g., Copper, Gold, Bismuth).

Electromagnetism

involves the physical interaction that occurs

between electrically charged particles. This section bridges the

concepts of electricity and magnetism.

ELECTROMAGNETS

A type of magnet in which the

magnetic field is produced by an

electric current. The magnetic field

disappears when the current is turned

off.

ELECTRIC MOTORS

Devices that convert

electrical energy into

mechanical energy by the

interaction between the

motor's magnetic field

and electric current in a

wire winding.

GENERATORS

Devices that convert

motive power

(mechanical

energy) into

electrical power for

use in an external

circuit (based on

Faraday's Law of

Induction).

TRANSFORMERS

Passive components that

transfer electrical

energy from one

electrical circuit to

another, or multiple

circuits, using

electromagnetic

induction. Used widely

in power grids to step

up or step-down

voltage.

wave

is a periodic disturbance that travels through space.

Mechanical Waves

Waves:Waves that require a physical, elastic

medium to propagate (e.g., sound waves in air, waves

traveling along a stretched string, seismic waves through

the earth). These waves are governed directly by

Newton's Laws.

Electromagnetic (EM) Waves

Waves:Waves that do not require

a physical medium to propagate. They can travel through

the absolute vacuum of empty space at the speed of light

Transverse Waves

wave in which the

displacement of the individual particles of the medium is

perpendicular to the direction of wave propagation (e.g.,

electromagnetic waves, waves on a plucked guitar string).

Longitudinal Waves:

A wave in which the

displacement of the individual particles of the medium is

parallel (along the same axis) to the direction of wave

propagation (e.g., sound waves, seismic P-waves).

Crest

The points of maximum positive displacement

trough

maximum negative displacement

Wavelength

The minimum distance between any two points on a wave that

behave identically (e.g., the distance from one crest to the next consecutive crest).

Measured in meters (m).

Period

The time interval required for one complete wave cycle to pass a given

point. Measured in seconds

Frequency

The number of complete wave cycles that pass a fixed point per

unit of time. Measured in Hertz (Hz),

Compressions

High pressure and high molecular density.

Rarefactions

Low pressure and low molecular density.

700nm

red lowest energy

400nm

violet highest energy

photons

Light behaves as packets of energy called

lambda

it represents the wavelength of the light (measured in meters)

index of refraction

. The ratio of the speed of light in a vacuum (𝑐) to its speed in a medium (𝑣)

Luminous Flux

The total perceived power of light emitted by a source.

Luminous Intensity

The luminous flux emitted per unit solid angle in each direction

candela

elemental unit of measurement in illumination, it is rigorously defined by the BIPM using precise physical constants.

Radiant Intensity

This represents the actual energy element before human eyes enter the equation.

Photopic Luminous Efficiency Function

exact "element" that bridges engineering and biology

V (kabaligtaran ng y)

is a standardized sensitivity curve of the human eye.

Illuminance

The luminous flux incident per unit area of a surface

Law of Reflection

The angle of incidence (𝜃1) equals the angle of reflection (𝜃′ 1), measured relative to the normal line.

Fiber optic cables

rely on TIR to transmit data over long distances with minimal loss.

Refraction

The bending of light as it passes from one medium with index 𝑛1into another with index 𝑛2

Angle of Incidence

Angle of the incoming light ray (Incident light)

Refracted light

angle of the bent light ray

Positive

concave mirrors, convex lenses

Negative

convex mirrors, concave lenses

Magnification

Positive means upright; negative means inverted.