Electricity Test Flashcards
Static Electricity
A stationary charge. It is standing without motion
What determines a Positive Charge, or a negative charge?
Matter is essentially neutral. However, in an event where an excess negative charge or positive charge is transferred to an object, the object will gain the charge that is in excess
Electrical Conduction in an Electroscope
A conductor is a material that transfers charges easily
In An electroscope: A negatively charged rod touches the electroscope. The positive charges travel up to the knob. The electrons go down to the leaves, and the leaves repel eachother and become negative
Electric Induction in an electroscope
Induction is when you create an electric charge on an object without touching it (temporary )
- Take negatively charged rod and keep it close to the knob
- The positive charge goes up to the knob.
- Th enegative charge goes to the leaves and then they repel eachothe r
Ground in an Electroscope
Ground: A connection where some charge can go without making impact
- Negative charge is held next to the knob.
- Positive charge goes up the the knob
- The negative charge goes to the leaves and to the wire.
Define
A. Conductor
B. Insulator
- Ground
Conductor: A material in which charges can move freely.
Ex. Wire, any metallicly bonded substance
Insulator: A material which blocks the movement of charges
Ex. Wood
Ground: A material that can hold charge without any significant change in its charge
Ex. Wire
What is Direct Current?
The current runs in one direction. Direct current is found in many low voltage appliance. Also, where batteries were used
What is Alternating Current
Alternating Current is: Current that runs in one direction for 1 sec. and then goes back in the original direction
This can be found in power lines
How does Dry and Wet Cell Battery work
- Container that is filled with acid
- Has 2 electrodyes in it. One is positive and one is negative
- If you run a current through it, then it will produce a chemical reaction in which one of the electrodyes is eaten at, and the remains settle onthe other
- There is energy..produced
- You connect a the two sides and you complete a circuit
IN A DRY CELL BATTERY, THE ACID IS PASTE
What kind of charges attract eachother? What kind repell
UNlike charges attract, like charges repel
What is Voltage, Current, and Resistance?
What are the units and symbols
Voltage: Electrical potential energy. The units are volts and the symbol is V
Current: Rate of movement of electric charge through a conductor. The units are amperes and the symbol is I
Resistance: Force that is opposed to movement of current. The units are ohms and the symbol is 1 ohm
What are Amps, Volts and Ohms?
Amps: Units for current, an ampmeter is used to measure
Volts:Unit used to measure Voltage, a voltmeter is used
Ohm: The resistance units, an ohmmeter
What is the relationship between resistance and conduction
V/I=R
What is Ohm’s Law?
When moving electrons collide, with atoms of the material, some of the kentic energy is transferred to the atoms. This energy transfer causes the atoms to vibrate and the material warms up. A conductors resistance indicates how much the motion of the charges within is rsisted within the it is resisted by the collisions. (RESISTOR IS A CONDUCTOR THAT AS A SPECIFIC TYPE OF RESISTANCE)
Ohms Law is V=IR you can plug values in to find the missing things
What is a series circuit? Parallel Cuircuit? What is an Incomplete?
What are fuses and circuit breakers
Fuses: An electrical device that contains a metal strip that melts when current in the circut becomes too great. This is used to prevent damages such as short circuits. It is part of the circuit. They cannot work in Parallel
Circuit Breakers: A switch that opens the circuit automatically when the current exceeds a certain value. It is basically 2 metals welded together. They are important for safety reasons.
What type of energy connects lights and sockets of a house
The Type of circuit that conects the lights and sockets of a house is a parallel circuit. This is because, in a series circuit, if one light went off then the whole power would go off.
What is electirc Power.how is it calculated?
Electric Power: The rate at which electric energy is used in a circuit. It is basically the rate at which electrical work is done. You can calculate it by using the equation: CurrentxVoltage P=I2R it is calculated using W anyway, you can notice that if you combine this equation with Ohms law, then the power lost, or dissipated by a resistor can be calculated.
What is electric energy
The energy that is associated with charged particles because of their positions. Instead of electric power which is the rate at which electrical energy is used. The units for electric energy are Joules
What is electric force?
It i the force of attraction or repulsion between objects due to charge..
Distance : Inversely proportionate If it is doubled, then the electric force: 1/x^2
Charge: Doubled, electric force is doubled
When charges are accelerated by an electric field to move to a position of lower potential energy, what is produced>
Cuttend
How do electrons move in a battery?
From the negative to the positive
What can current be made up of?
Positive and negative charges in motion
Conventional Current
The current made of positive charge that would have the same effect as the actual motion of the charge in the material. The direction of current will always be given as the direction of positive charge movement that is equivalent to the actual motion of charges in the material
IN which way do electrons move relative to the field lines?
They move inward
What indicates more force in an electric field diagram?
More lines
