Current And Voltage Flashcards
What is current?
The quantity of electricity flowing through a conductor.
What is voltage?
The pressure of electricity flowing through a conductor.
What holds electrons in orbit?
Force of attraction.
What makes up a nucleus?
Protons and neutrons.
Whats the relationship between protons neutrons and electrons in a balanced atom?
There will be an equal number of protons neutrons and electrons.
What is the outer orbit of an atom knows as?
Valance shell.
What is the electron in the outer orbit known as?
Valance electron.
What causes current?
When outer electrons are forced out of orbit they will wander amongst other atoms. These electrons are called free electrons, and their movement from one atom to another produces current.
What is the difference between conductors and insulators?
In conductors, very little energy is needed to force electrons out of their orbit. Therefore current flows easier.
In insulators, electrons are not dislodged as easily and very little to no current can flow.
When an electron leaves an atom, what is this atom known as?
Positive ion.
What are electrons attracted and repelled by?
Attracted by positive charge, repelled by negative charge.
Which direction is flow?
Negative to positive.
What is conventional current flow?
Flow from positive to negative. Believed to be true in the early days.
What is the unit of measurement of current?
Ampere - A
What is an amp?
The amount of electrons passing a given point in one second.
What is one amp equal to?
6.241x10 to the power of 18.
What is caused by current flow?
Heat and a magnetic field around the conductor.
Whats the circuit symbol for current?
I
When does potential diffence exist?
Between two points in a circuit with a difference in charge.
What force drives a current around a circuit?
Electromotive force (EMF)
Whats causes potential difference?
Inbalance of electrons at different points.
Where are voltmeters and ammeters placed?
Voltmeter - outside circuit
Ammeter - inside circuit
What are six methods which produce voltage?
Chemical Friction Induction Pressure Heat Light
What is the material in solar panels?
Semiconductor
What is a thermocouple?
When two wires of different metals are welded at each end and the two ends brought to different temperatures. Electric potential is produced between them.
What does the amount of voltage produced by a thermocouple dependent on?
The difference in temperature and the type of materials used.
