LAST NA TO PHYSICS!!!!!

CURRENT

Movement of particles are affected by the ELECTRIC FIELD.

CURRENT

Coulomb per sec or AMPERE (A).

CONVENTIONAL CURRENT

Current flows from positive back to the negative side.

ELECTRON FLOW

From NEGATIVE to POSITIVE.

DIRECT CURRENT (DC)

FLOWS IN ONE DIRECTION.

ALTERNATING CURRENT (AC)

CHANGES DIRECTION PERIODICALLY.

RESISTANCE

opposition of the material to the flow of charge carriers.

RESISTANCE

resistance to the flow of charge.

RESISTANCE

VOLT PER AMPERE OR OHM.

RESISTOR

device that contributes appreciable resistance to the flow of charge.

VOLTAGE

Potential difference.

VOLTAGE

required energy to move the unit charge from one point to other.

VOLTAGE

VOLTS.

ELECTROMOTIVE FORCE (EMF)

It is the energy supply to the charge BY A BATTERY CELL.

ELECTROMOTIVE FORCE (EMF)

is the maximum potential difference between two terminals of a battery when no current is flowing from the source.

OHM'S LAW

current in a circuit is directly proportional to the electric pressure and inversely to the resistance of the conductors.

OHM'S LAW

direct proportionality between current and voltage but inversely proportionality between current and resistance.

ELECTRIC WORK

amount of energy required to transfer a charge through a potential difference.

ELECTRIC WORK

JOULE.

ELECTRIC POWER

rate at which energy is delivered by a source as it carries charge through a potential rise in a time.

ELECTRIC POWER

How fast energy is delivered/used.

ELECTRIC POWER

WATT.

PHYSIOLOGICAL EFFECTS OF CURRENT

Standard voltage of outlets in phil is 220V.

PHYSIOLOGICAL EFFECTS OF CURRENT

Plugging 110V to 220 V? In most appliances, It will develop more heat and probably burns out in minutes.

PHYSIOLOGICAL EFFECTS OF CURRENT

Plugging 220 V to 110 V? It will normally last longer before it dies or in some instances, will fail to start.

RESISTORS IN SERIES

WHEN CURRENT CAN FLOW ONLY ONE PATH AS IT FOLLOWS THROUGH TWO OR MORE RESISTORS CONNECTED IN LINE.

RESISTORS IN PARALLEL

SEVERAL RESISTORS ARE CONNECTED IN PARALLEL BETWEEN NODES IF ONE END OF EACH RESISTOR IS CONNECTED TO ONE NODE AND THE OTHER END OF EACH IS CONNECTED TO OTHER NODE.

MAGNET

Has two magnetic poles: North Pole (N) and South Pole (S). Each magnet has its own magnetic field.

MAGNETIC FIELD

Made up of imaginary field lines, similar to electric fields, which describes magnetic force in a given region. The field lines form loops inside the magnet.

MAGNETIC INTERACTION

In magnets, like poles repel and opposite poles attract, just like the electric charges, however, charges can be isolated. If you cut a magnet into two pieces, each piece will still have two poles.

COMPASS

A magnetic field is detected by its effect on a compass' magnetic needle. Compass needle is always pointing to the north.

EARTH'S MAGNETIC FIELD

Due to large amount of magnetized material on the core, Earth's magnetic field is immense, expanding to the outer space called the magnetosphere.

This magnetic field protects Earth from harmful particles coming from the sun (called the solar wind).

Northern Lights (Aurora Borealis) and Southern Lights (Aurora Australis).

MAGNETIC DOMAINS

Magnet is actually made up of tiny regions called magnetic domains, typically 1 square millimeter in area. Each domain has their own set of poles. The presence of magnetic field in ferrous materials affects the domain as it lines up with the field.

KINDS OF MAGNETS

Permanent Magnets, Temporary Magnets, Electromagnets.

PERMANENT MAGNETS

A kind of magnet where objects remains attracted even removed from the other magnetic field of another object.

TEMPORARY MAGNETS

A kind of magnet where objects will repel once removed from the other magnetic field of another object.

ELECTROMAGNETS

Magnets can be useful if there's a presence of electric current.

NON-MAGNETIC MATERIALS

If materials are not magnetized in the presence of electric field and domains cancel out each other, they are called to be non-magnetic. Wood, plastic, glass, etc.

CONNECTION OF ELECTRICITY AND MAGNETISM

An electric current produces a magnetic field. When current runs through an electric wire, the magnetic field circles around the wire. Electricity and magnetism are essentially two aspects of the same thing, because a changing electric field creates a magnetic field, and a changing magnetic field creates an electric field.

FIRST RIGHT HAND RULE

The thumb of the right hand points to the North Pole of the solenoid when the hand is wrapped in the same way as the electric current around the solenoid.

MAGNETIC FIELD STRENGTH (B)

The strength of magnetic field can be measured whenever there is a current flowing on a wire. Unit: Tesla (T)

SOLENOID

An electromagnet that generates a controlled magnetic field through a coil wound into tightly packed helix.

MAGNETIC FLUX

is the measure of the total magnetic field that passes through an identified area perpendicular to the magnetic field. Instrument: Magnetometer. SI unit: Weber (Wb). 𝜙 = 𝐵𝐴.

MAGNETIC FORCE

The magnetic field exerts a force on a current-carrying wire in a direction. This force can easily be large enough to move the wire, since typical currents consist of very large numbers of moving charges. SI unit: Newton (N). 𝐹 = 𝐼𝐿𝐵 sin 𝜃.

SECOND RIGHT HAND RULE

If you point your pointer finger in the direction the positive charge is moving, and then your middle finger in the direction of the magnetic field, your thumb points in the direction of the magnetic force pushing on the moving charge.

AMPERE'S LAW

The magnetic field created by an electric current is proportional to the size of that electric current with a constant of proportionality equal to the permeability of free space.

ELECTROMAGNETIC INDUCTION

It is the production of an electromotive force across an electrical conductor in a changing magnetic field. It also causes the change in magnetic flux.

ELECTROMOTIVE FORCE

is not a force, it is the potential difference or the potential energy per charge. It is what causes the electron to move and form the current.

FARADAY'S LAW

The induced emf in a closed loop is equal to the negative of the time rate of change of the magnetic flux through the loop.

LENZ'S LAW

An induced current that induces a counter magnetic field opposes the magnetic field generating a current.

ELECTRIC MOTOR

transforms electrical energy to mechanical energy.

MOTOR

consists of loops of wire in a magnetic field. When current passes through the loops, the magnetic field exerts a torque on the loops and converts the electrical energy to mechanical energy, that makes the rotation of the loops of wire.

KINDS OF ELECTRIC MOTOR

DC Motors and AC Motors

GENERATOR

transforms mechanical energy to electrical energy.

GENERATOR (Mechanism)

The _____ consists of loops of wire wrapped around an iron core (solenoid) and placed in a magnetic field. The armature is mounted on the wire, so it can rotate in the magnetic field. As the armature spins using up mechanical energy, the loops of wire cut across the field and produce electric current (induction). The produced current of a generator is called alternating current.

BACK-EMF

is the voltage generated during the operation of a rotating machine (a generator or a motor).

Transformer

is a device that helps transfer electrical energy through electromagnetic induction.

Primary Coil

The coil in a transformer that is connected to the AC voltage source.

Secondary Coil

The coil in a transformer where the induced EMF is generated.

Step-up Transformer

The secondary voltage is larger than the primary voltage.

Step-down Transformer

The secondary voltage is smaller than the primary voltage.