Static Electricity
Calculations
Circuits
SURPRISE
Generating Power
100
What are the three ways you can charge something statically?
Charging by Friction Charging by Induction Charging by Contact
100
A television, plugged into a wall, has the potential difference of 120V. If the television uses a current of 1.45A, what is its resistance?
82. 76 ohms
100
Draw a circuit that contains two bulbs in series, a switch, and a battery.
100
Explain why a wire is made of copper and coated with a plastic coating
100
Name 3 sources of renewable energy
biomass, geothermal, wind, solar
200
Using the electrostatic series, answer this question. What charge will cotton and nylon have when rubbed together?
Cotton - negative Nylon - positive
200
What is the percent efficiency of an appliance that has 45kJ of useful energy output and 125kJ of total energy output
36%
200
Fill in the blanks: A voltmeter must be connected in ______________ to measure the __________________________ while an ammeter is connected in _______________ to measure ____________________.
parallel, potential difference/voltage, series, current
200
If you do not want static electricity in your hair, should you use an aluminum brush or a plastic brush? Why?
200
What is a transformer?
an electrical device that lowers the voltage of the electricity delivered to your house.
300
Name two applications to static electricity and how they work.
300
Looking at the circuit drawn on the board, calculate the missing resistance, current and potential difference.
300
Draw a circuit diagram where there are three bulbs in series, a switch, and a battery. What happens if you unscrew one of the bulbs?
lights turn off
300
A conductor that does not obey the Ohm's law is called
nonohmic
300
What is a circuit breaker and how does it work?
safety device that is set to a specific current limit. When current is too large, it heats and bends a part of the circuit breaker, causing the circuit to become open. Must be reset.
400
Draw a diagram to explain how charging by induction works
400
Janice is comparing the efficiency of two different dishwashers. She calculates that the energy to do one load of dishes is 430kJ. The first dishwasher has a power rating of 2.1kW and took 20 minutes to wash the dishes. The second dishwasher has a power rating of 3.1kW and took 25 minutes to do the dishes. Which dishwasher is more efficient?
dishwasher 1 - 17% dishwasher 2 - 9.2%
400
Explain the relationship of potential difference, voltage and current in a series circuit.
400
If no resistance is felt in the conductor, it is called ______________________
superconductor
400
Name two disadvantages and two advantages of using nuclear fuel for electricity.
disadvantages - stations expensive to build, non-renewable advantages - produce no greenhouse gases, can produce a large amount of energy with small amount of fuel
500
There are four pith balls. Pith A is attracted to Pith B. Pith D is negatively charged Pith C is attracted to Pith D. Pith B is attracted to Pith D and Pith C. Determine if each Pith is positive, negative or neutral
Pith D - negative Pith C - neutral Pith B - positive Pith A - negative
500
Calculate the cost of watching TV for 3 hours at night at a rate of 8.8cents/kWh. The television has a power rating of 150W
500
Explain how the resistance of a circuit would change if a) The wire got thicker b) The wire got shorter c) If the temperature was hotter
a) decreases b) decreases c) increases
500
Define the different cells - dry cell vs wet cell - primary vs secondary cell - fuel cell - solar cell
500
Draw a flow chart of how electricity for your coffee machine gets to your house. Assume that the electrical energy is generated from hydroelectric dams.
water --> turbines --> electrical towers --> transformers --> meter --> distribution panel --> coffee machine
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