GENERAL PHYSICS 2: CONCEPTS

CONVENTIONAL CURRENT

Electric current moves initially in the positive toward the negative terminal of the source of electrical potential.

ELECTRIC FLOW

Actual flow of the electric current is actually the negative toward the positive terminal of the source.

SERIES CIRCUIT & PARALLEL CIRCUIT

Give the two types of Circuit

SERIES CIRCUIT

It follows only one path, and each electrons must go through each load connected to the circuit.

PARALLEL CIRCUIT

The electrons are distributed over several paths through the circuit, and may pass through any one of the several loads in the circuit.

OHM'S LAW

Developed by Georg Simon Ohm. For a given conductor, the ratio V/I is a constant.

E\=VIt

As electron flows through a circuit, the energy they receive dissipates. This dissipation of energy is expressed through what equation? (formula)

KIRCHHOFF'S LAW

Developed by Gustav Robert Kirchoff. Applied two fundamental conservation laws to electric circuits.

CONSERVATION OF ENERGY

Electrons gain energy as they pass through a source but loses energy through loads. The total energy gained throughout the whole circuit is equal to the total energy lost.

CONSERVATION OF CHARGE

No electric is created or destroyed in an electric circuit. It does not accumulate at single point along the circuit.

KIRCHHOFF'S VOLTAGE LAW (KVL)

The total increased electric potential is equal to the total decreased electric potential.

KIRCHHOFF'S CURRENT LAW (KCL)

As an initial current pass through a junction, the distributed total electric current is equal to the initial current.

POWER

The amount of energy used or supplied over time. And the rate at which the appliance consumes electrical energy; is obtained by multiplying the voltage by current.

P\=VI

If the load has a resistance, then its power may also be expressed using Ohm's Law as? (formula)

MAGNETISM

The ability of a magnet material to attract other magnetic materials. Only occurs between magnetic materials.

MAGNET

A material that possesses magnetism. May be natural or artifact.

LAW OF MAGNETIC POLES

Two same magnetic poles repel one another while two opposite magnetic poles attract.

FIELD FORCE

Magnets should be close to one another.

MAGNETIC FIELD

A magnet can produce what? Also known as the location around a magnetic material. It is the region of space where a magnet is capable of exerting a force on a magnetic material. (B). From North to South poles.

MAGNETIC DECLINATION

The true north is when there is a change in angle from the perceived north.

MAGNETIC COMPASS

An instrument used in determination of the true north and south poles.

RIGHT-HAND RULE

Placing the thumb and the other fingers in a 90° angle, the thumb represents the velocity while the other fingers represent the magnetic field. The force on the charge is straight out of the palm.

MASS SPECTROMETER

Uses the equation above to separate equally ionized atoms of different masses.

TORQUE

This can be produced if a loop of current is pivoted and turned within a magnetic field.

MAGNETIC MOMENT

Can be used to determine the amount of torque produced by a current.

GALVANOMETER

Measures the current of a loop.

AMMETER

From the concept of galvanometer, \_______ was developed in parallel with a resistor to measure the current.

BIOT SAVAT LAW

Mathematical equation which determines the magnetic field.

AMPERE'S LAW

States that the total sum of products of the magnetic field and length elements are equal to the current multiplied by permeability constant.

SINGLE LOOP

Through the Ampere's Law, the magnetic field can be found using the equation wherein r is the radius of the loop.

SOLENOID

Current form as a straight coil of wire.

TOROID

Similar to the solenoid, it also shows the dependency on the number of turn of loop. It forms a circular path.

AMPERE'S LAW APPLICATION

Magnetic flux describes the magnetic field passing through a surface.

LORENTZ FORCE LAW

An electromagnetic force produced by the electric field and the magnetic field.

LEFT-HAND RULE

Used to analyze the magnetic field and the electron flow. The magnetic field would simply be pointed at the opposite direction. The thumb is depicted as the electron flow while the magnetic field are the curled fingers around the conductor.

UNIFORM MAGNETIC FIELD

Can be seen when the magnetic field lines are straight and point in the same direction.

MAGNETIC FIELD STRENGTH

It is dependent on the current in the coil, number of loops in the coil, and type of core material.

MAGNETIC PERMEABILITY

Factor by which a core material increases the magnetic field strength.

FERROMAGNETIC

Materials become strong in boost magnets when placed in a coil, and as a recruit have high permeability. (Iron, Nickel, Cobalt).

PARAMAGNETIC

Substances magnetize very slightly when placed in a coil and increased the full strength by a barely measurable amount. They have permeability only slightly greater than 1. (Oxygen, Aluminum).

DIAMAGNETIC

Substances cause a very slight decrease in the magnetic field of a coil. The permeability is less than 1. (Copper, Silver, Water).

ELECTROMAGNET

Used to cause another component to move through a magnetic field.

MICHAEL FARADAY

Who devised an electromagnet motor as early as 1822?

MOTOR PRINCIPLE

As a current carrying conductor moves across a magnetic field, a force perpendicular to the magnetic field and the electron flow is produced which is dependent on three factors; the magnetic field, the current, and the angle between them.

ELECTROMAGNETIC INDUCTION

The process of producing an induced electromotive force due to a change in magnetic flux.

FARADAY'S LAW OF ELECTROMAGNETIC INDUCTION

If the magnetic field changes, it causes the electrons to be induced to flow through the conductor.

MUTUAL INDUCTION

Occurs when a current induces another current.

ELECTRIC CURRENT

Can be produced from moving or changing magnetic field. Why? It causes electrons to flow.

INDUCED POTENTIAL DIFFERENCE

Can be generated from a change in magnetic field.

FARADAY'S LAW

Induced electromotive force in a close loop is equal to the rate of change of magnetic flux through the loop.

FARADAY'S FIRST LAW

Displacing a magnet within or far away from a coil. Displacing a coil within and away from the magnetic field. Altering the area of the coil within a magnetic field.

HEINRICH LENZ

He reasoned that when a current is induced, it produces a magnetic field. This magnetic field, which call the induced field, them interacts with the inducing field, either attracting or repelling it.

LENZ'S LAW

The induced field produced by an induced current produces an action from the inducing field.

ALTERNATING CURRENT (AC) GENERATOR

By positioning a coil a wire between two magnets, as the coil of wires are rotated, it forms an electric generator.

GENERATOR

A device that converts mechanical energy to electrical energy. It is a coil of a number of loops rotating in a magnetic field.

DIRECT CURRENT (DC) GENERATOR

By replacing the construct of an AC generator and using only a single split ring, or commutator, with two brushes, the simplified generator will appear.

TRANSFORMER

A simple device that is capable of changing electric potential.

STEP UP/DOWN TRANSFORMER

Depends on the number of turns in the primary and secondary coil.

MIRRORS

Any smooth reflecting surface which is capable of reducing images by reflection of light.

PLANE MIRRORS

It has a flat surface.

SPHERICAL MIRRORS

It is a portion of reflecting sphere.

CONCAVE MIRROR

The reflecting surface is the inner portion of the sphere. Converging mirrors. (Reflected rays meet at a point).

CONVEX MIRROR

The reflecting surface is the outer portion of the sphere. Diverging mirrors. (Spread out light rays).

PLANE MIRROR IMAGES

Any light ray incident on a plane mirror will be reflected in accordance with the law of reflection. Always virtual and upright relative to the object.

CENTER OF CURVATURE (C)

Center of the sphere where the mirror was taken.

VERTEX (V)

Center or the mirror.

RADIUS OF CURVATURE (R)

The radius of the sphere; distance between the center of curvature (C) and the Vertex (V).

PRINCIPAL AXIS OR OPTICAL AXIS

Straight line joining the center of curvature (C) and the Vertex (V).

APERTURE (AB)

Width of the mirror.

PRINCIPAL FOCUS OR FOCAL POINT (F)

It is where the reflected rays meet (for converging mirrors). And it is where they seem to come from (for diverging mirrors).

FOCAL LENGTH (f)

Distance from the Vertex (V) to the Principal Focus or Focal Point (F). Since F is halfway between the Center of Curvature and the Vertex, f\=R/2

MAGNIFICATION (m)

Ratio of the image distance and object distance to the ratio of the image height and the object height.

SPHERICAL LENS

A piece of glass or transparent material having at least one spherical surface. (Divided into concave and convex).

CONVEX LENSES

Thicker on the middle than the edges. Converging lenses..

CONCAVE LENSES

Lenses are thicker on the edges/side than the middle.

PRINCIPAL FOCUS (F) (spherical lenses)

The point where the beam of parallel rays falling on a convex lens converges.

SECONDARY FOCUS (F') (spherical lenses)

When parallel rays enter the optical surface, they will focus at the secondary focal point.

OPTICAL CENTER (P)

Point where all light rays pass through without being bent.

PRINCIPAL AXIS

Line joining the optical center and the principal focus.

FOCAL LENGTH (f) (spherical lenses)

Distance from the optical center of the lens to the principal focus.

EYE

Opaque ball averaging to 2.3m in diameter.

CORNEA

Outer thin transparent membrane of the eye ball. It protects the eye and refracts most of the incident light.

PUPIL

Black circle in the middle of the eye.

IRIS

The colored circle of the eye.

CRYSTALLINE LENS

Clear convex at the back of the pupil.

CILIARY MUSCLES

These relaxes when the lens focuses on distant objects.

RETINA

Light-sensitive layer of the tissue lining the back of the eye.

MASCULA

The oval-shaped pigmented area near the center of the retina.

FOVEA

Region of the most distinct vision.

ACCOMODATION

Ability of the eye to focus on objects at different distances.

FARSIGHTEDNESS

Defect in the eye in which the image of nearby objects cannot be focused on the retina.

ILLUMINATION (E)

Amount of light energy that radiates per second over a surface area.

REAL IMAGE

It can be formed on a screen.

VIRTUAL IMAGE

Created by apparent intersection of reflected light rays, when they are extended backward, behind the reflecting surface.

NORMAL

Construction line drawn at right angles to a surface at a point of incidence.

DECREASES

When light enters a medium more optically dense than air, its speed \_________.

INDEX OF REFRACTION (n)

The ratio of the speed of light in air to the speed of light in the medium. A new property of the medium: ratio of the speed of light and velocity.

WHITE (LIGHT)

It reflects light.

BLACK (OBJECTS)

It tend to absorb light.

SUBTRACTIVE THEORY OF COLOR

The colors of the spectrum are subtracted by filters or dyes until the desired color remains.