Learning Task 1-12 Flashcards
In a carbon Atom what is the outer shell called
Valence orbit
How many valence electrons can you find in a semi-conductor?
4 valence electrons
The fundamental laws of charged bodies?
- Like charges repel and unlike charges attract.
- The force between two charges at rest is directly proportional to the product of the magnitudes of the charge. And inversely proportional to the square of the distance between them.
List six methods of producing electricity?
Heat Magnetism Pressure Light Friction Chemical
How many electrons are equal to one coulomb?
6.24x10 to the power of 18
What is voltage
Potential energy difference.
What is resistance?
Opposition to current which converts electric energy into heat energy.
What is polarity?
The charge at one point with respect to another.
What is ohm?
Base unit of resistance.
What is power?
Rate of doing work or using energy.
What is ohms law?
The current flowing in a circuit is directly proportional to the voltage and inversely proportional to the resistance.
Electrons flow from?
- to +
Conventional flows from?
+ to -
What is EMF?
The work per unit charge done by a source on the electric charges, to move them against the electric field.
What is the law of conservation of energy?
Energy may never be created or destroyed. Electrical energy always come from some other form of energy.
List 4 main types of electrical drawings?
Pictorial diagram
Block and one-line diagram
Wiring diagram
Schematic diagram
What three things do you need to complete a circuit?
Source
Load
Conductor
What is short circuit?
A parallel path of low resistance.
The type of reading error that takes place when you don’t look at the needle straight on is called?
Parallax
What is the carbon composition resister colour table.
Colour of bands?
Black- black Brown- beer Red- rots Orange- our Yellow- young Green- guts Blue- but Violet- vodka Grey- goes White- well Gold- get Silver- some No colour- now
What are three types of fixed resisters?
Wire round resister
Film resister
Carbon composition resister
What resister has the lowest watts rating?
Carbon composition resister
Why is it important to switch contacts quickly?
To minimize arcing and burning of contacts.
What accelerates the opening and closing of the contacts?
A spring action
What are the three main classes of resisters?
Fixed resisters
Variable resisters
Adjustable resisters
How are adjustable resisters adjusted?
Sliding collar being locked at some point on the coil to give it the desired resistance.
What is the difference between an atom and a molecule?
A molecule must be independent but the atom does not have to be.
A substance that is made up of Atoms of more then one type is a?
Compound.
Anything that occupies space or has mass is referred to as?
Matter.
The smallest portion an element can be broken down into and still posses the properties of that element is referred to as an?
Atom.
% efficiency equals what?
Output watts / input watts X 100.
State watts law.
The power in a circuit equals the product of the voltage and the current in the circuit.
1 horse power is equal to how many watts?
746 watts
Voltmeters are connected in?
Parallel.
Ammeters are connected in?
Series.
