Q2: Science Long Test 1 Flashcards
What is electricity?
the interaction of electric charges
Do protons have a positive or negative charge?
Positive
Do electrons have a positive or negative charge?
Negative
What is the law of electric charges?
The attraction or repulsion between objects.
Definition of static electricity
The build up of electric charges on an object
What is electric discharge
The release of electrons from a fully charged object to a positive charged object known as the conductor
What is an electric current
The flow of electrons - this can be on a conductor
Direct Current (DC) Definition
The flow of electricity in one direction only.
Alternating Current (AC) Definition
Flows in one direction, then reverses repeatedly.
What is a conductor?
A material that allows current to flow through easily
What is an insulator?
A material that resists the flow of electric current.
He was the one who discovered that electric currents produce a magnetic field
Hans Orested
They discovered that if an electric current produces a magnetic field, then a changing magnetic field creates an electric current.
Michael Faraday and Joseph Henry
What is an electromagnet?
A coil of wire around an iron rod
What is induced EMF
EMF created because of the change in the magnetic environment around the conductor
Define EMF
The “force” that pushes electrons through the conductor, creating an electric current || However, there is not really any force, it’s just pressure.
This law states that the change in strength of magnetic field (magnetic flux) induces a current, hence creating induced emf
Faraday’s Law
This law states that the magnetic field of the induced current will push back/repel against the change of the original magnetic field
Lenz Law
What does Coulomb’s Law state?
The size of charges and distance between electric charges are the factors in determining the strength of the electric force.
Function of Magnets in an AC Generator
The magnet is used as an magnetic field to create electricity
Function of Armature Coil in an AC Generator
Produces an electric current when it turns in a magnetic field
Function fo Slip rings in an AC Generator
Used to transfer electric power from stator to circuit
Function of Carbon Brushes in an AC Generator
Conducts an electric current, and makes contact with slip rings
Function of the load in AC generator
thing being powered by the generator
Function of Magnets in DC Generator
The stator which is the stationary component found in electric motors and generators
Function of Armature Coil in DC Generators
Connected in series to enhance the sum of current
What happens to Mechanical energy in a Motor/Generator
Gets converted into Electrical Energy
Function of Commutator/Slip Ring in a DC Generator
Applies an electric current to the windings
What are the 3 stages in producing electricity?
Generation, Transmission, and Distribution
Describe the step down transformer
More coils on the primary side than the secondary side
3:1 ratio
Describe the step up transformer
More on the secondary side, less on the primary side
1:3 ratio
Explain how the transformer operation works.
When AC Voltage is applied to the primary coil, the current flows through it creating a change in magnetic field.
- The magnetic core guides the change of magnetic field
- the magnetic field circles the secondary coil and induces a magnetic current. → the result of this is that the voltage applied to the primary coil is therefore transformed into a different voltage in the secondary coil.
Explain Mutual Inductance
Principle which allows transformers to work.
An Electric Motor does what?
Does the reverse of a generator: Changes electrical energy into mechanical energy.
