Unit 5 — Electricity And Magnetism Flashcards
(37 cards)
The rate of transformation of electrical energy.
Electrical power (P)
The change in electric potential energy associated with charges at two different points in a circuit.
Electric potential difference (V)
J/C
Electrical device that measures electric current; must be connected in series.
Ammeter
A property of matter that describes how difficult it is for electric current to travel through a material.
Factors that affect it (4):
Electrical resistance (R)
1. Diameter of conductor. 2. Length of conductor. 3. Material. 4. Temperature.
The total resistance of a group of resistors connected in series or parallel.
Equivalent resistance
Measure of electrical energy.
3.6 x 10^6 J
Kilowatt hour (kWh)
Electrical device that measures electrical potential difference.
Voltmeter
In any complete path in an electric circuit, the total electric potential increase at the source(s) is equal to the total electric potential decrease throughout the rest of the circuit.
Kirchhoff’s Voltage Law (KVL)
The potential difference between any two points in a conductor varies directly with the current between two points if the temperature remains constant.
Ohm’s Law
The amount of electric potential energy associated with charges.
Electric potential
The movement of electrons in only one direction.
Direct current (DC)
An electrical device that has a specific resistance value.
Resistor
A device that measures electrical resistance.
Ohmmeter
A region of space around a magnet that causes a magnetic force on magnetic objects.
Magnetic field
Whenever a charge moves through a straight conductor, a circular magnetic field is created around the conductor.
Oersted’s principal
-‘ve to +’ve.
Electron flow current
The fingers of your right hand wrap around the coil in the direction of the conventional current, while your right thumb points in the direction of the north magnetic pole of the coil.
RHR for solenoid
If you hold a straight conductor in your right hand with your right thumb pointing in the direction of the conventional current, your curled fingers will point in the direction of the magnetic field lines
RHR for straight conductor
A coiled conductor.
Solenoid
If the fingers of your open right hand point in the direction of the external magnetic field and your thumb points in the direction of the conventional current, then i to faces in the direction of the force on the conductor.
RHR for the motor principle
+’ve to -‘ve.
Conventional current
Any device that produces a magnetic field as a result of an electric current.
Electromagnet
A current-carrying conductor that cuts across external magnetic field lines experiences a force perpendicular to both the magnetic field and the direction of the electric current
Motor principle
In a closed circuit, the amount of current entering a junction is equal to the amount of current exiting a junction.
Kirchhoff’s Current Law (KCL)
