Static Electricity
Which of the subatomic particles can move from object to object, and therefore are responsible for the overall charge on an object?
Electrons
What is the device that transforms electrical energy into other usable forms of energy called? Provide an example.
Load.
Example: light bulb
Provide a real-life example of a series circuit and parallel circuit.
Series: christmas lights or coffee maker
Parallel: headlights
What is the formula for Ohm's Law?
V = I x R
R = V / 1
I = V / R
What does the law of electric charge state?
Similar charges attract.
Opposite charges repel.
If two substances are charged by friction, what determines which object will become negatively charged?
Triboelectric series chart
In a battery, what is the conducting solution called?
Electrolyte
Draw a circuit diagram showing an electric cell, a switch and three lamps connected in series.
Teacher must verify drawing.
A light bulb has a resistance of 16 Ω If there is a current of 2.4 A flowing through it, calculate the voltage that is transferred to the bulb.
V = 38.4 V
How do loads connected in series impact resistance?
Increases the total resistance of the circuit.
What are the three methods used to charge an object?
1) Induction 2) Friction and 3) Conduction
What is the unit for electrical energy. That is, the energy provided by the flow of electrons in an electric circuit?
Joules (J).
Energy = V x I x t where
V = voltage
I = current
t = time
What three characteristics of a wire impacts it's resistance?
1. Thickness
2. Material
3. Length
What three devices are used to measure current, resistance and voltage in an electrical circuit? Do they need to be connected in series or in parallel?
Ammeter = series
Ohmmeter = parallel
Voltmeter = parallel
Name three renewable energy sources.
Define electrical insulator. Give two examples of good insulators. Define electrical conductor. Give two examples of good conductors.
Answers may vary.
What are the two main sources of electrical energy?
1. Batteries.
2. Electric Generating Stations
If the resistance of a circuit with 12 A is doubled without changing the voltage, what will be the new current in A?
6 A
A small LED circuit draws 25 mA of current when connected to a 9 V battery. What is the resistance of the circuit?
R =360 Ω
A series circuit has three lamps. The potential difference of the battery is 30 V. What is the potential difference across each lamp?
10 V
Draw a diagram of a negatively charged ebonite rod coming in contact with a neutral piece of wood.
Teacher must verify drawing.
Describe and explain the the form of current electricity used by wall outlets.
Alternating current (AC):
- Electrons move back and forth, alternating their direction.
- Produced by generators
- Wall outlets provide this type of current
A measure on 1A means how many electrons are travelling through the ammeter every second?
6.2 × 1018 electrons per second
For a circuit of 3 identical lights connected in parallel, what happens to the effective resistance of the circuit if another light is connected in parallel? What happens to the total current? What happens to the brightness of the lights (in theory)?
1. Resistance Decreases
2. Current Increases
3. Brightness of each light stays the same
What is the difference between primary cells and secondary cells?
Primary cells: Can only be used once. Must be replaced. Examples: Lithium Cells. If not used, can have a shelf life up to five years.
Secondary cells: Can be recharged and reused many times before they are used. Harmful for the environment and must be recycled properly. Examples: Lead-acid batteries (in cars).