Unit 2-Electricity Flashcards
What is an insulator?
A substance that does not allow electrons to flow through it. Static electricity can build up on an insulator. Examples: hair, plastic and rubber
What is an conductor?
A substance that allows the free flow of electrons through it. Static electricity does not build up in a conductor. Example: metals
What is an electric charge?
A negative or positive charge the exerts an electric force.
How to make an electric charge?
Remove electrons: substance becomes positive
Add electrons: substance becomes negative
What is friction?
The force resisting the relative motion of two surfaces in contact. Friction can remove electrons from one object and cause them to transfer to the other.
What are the laws of electric charges?
- Opposite charges attract
- Like charges repel
- Charged objects attract neutral objects.
What is the electrostatic series law?
When changing by friction occurs, the substance higher on the list always loses electrons and becomes positively charged. The substance lower on the list gains electrons and becomes negatively charged.
Which substance will become positive and which will become negative?
Fur and ebonite
Look at chart*
Fur positive
Ebonite negative
Which substance will become positive and which will become negative?
Rubber and sulfur
Look at chart*
Rubber positive
Sulfur negative
Which substance will become positive and which will become negative?
Wool and cotton
Look at chart*
Wool positive
Cotton negative
2 important facts about a parallel circuit.
- In a parallel circuit, the electrons have more than one path to follow.
- In a parallel circuit, the appliances do not share the electrical pressure.
True or false?
A dry cell gives static electricity?
True
True or false?
Static electricity lights our homes?
False
Static electricity causes lighting?
True or false?
True
How many path does a series circuit have to follow?
1
What is static electricity?
Charge/electrons are stationary
Generated by friction
What is current electricity?
Electrons are moving/ flow in a circuit
Generated through the conversion of energy forms.
What do electrons travel through allowing us to do work?
Circuits
What is the formula to find resistance?
R=V/I
What is the formula to find ohms.
I= V/R
What is the formula to find volts?
V=IxR
What is the problem solving method we use?
G(given) R(required) A(analyze) S(solve) p(paraphrase)
A current of 4 A flows through a 40 ohm resistor in a circuit. What is the voltage?
G- I=4A, R=40 ohms R- find the voltage A- V=IxR S-v= 4x40 =160v P- the voltage of the resistor is 160v
Is= I1=I2=I3= is what type of circuit?
Series
Vs= v1+v2+v3+ is what type of circuit?
Series
Reqivalent= R1 + R2+R3 + is what type of circuit?
Series
Is=I1 + I2+ I3 + is what type of circuit?
Parallel
Vs= v1 =v2=v3= what circuit is this?
Parallel
1 = 1 + 1 + 1
Requivalent R1 R2 R3
Is what type of circuit?
Parallel
How do you find efficiently?
UEO x100 TEI UEO- useful energy output TEI- total energy input
A light bulb uses 100 J of electrical energy and produces 35J of light energy. Calculate the percent efficiency of the light bulb.
G- TEI= 100 J, UEO=35J
R- find % efficiently
A- % eff=UEOx100
TEI
S- 35/100x100 =35%
P- the efficiency of the light bulb is 35%.What is on peak cost
.18/kWh
What is off peak time?
$0.0087
Name the quantity, the symbol of quantity, the unit and symbol.
- Potential difference= V= Volt (V)
- Energy= E= Joules (J)
- Resistance= R= Ohms (J)
- Current= I= Amps (A)
- Power= P= Watts (W)
- Charge= Q= coulombs (C)
How to do the long questions?
- Covert W into Kw by dividing by 1000
- Multiply KW with hour per a dayx how many days you use it.
- Times your answer with the onpeak price and off peak price
- Subtract
