Energy Basics
What is the Law of Conservation of Energy?
A: Energy cannot be created or destroyed; it can only be transformed or transferred.
100: What symbol represents a battery in a circuit diagram?
A: A long line and a short line placed in parallel.
100: What is Ohm’s Law?
A: V = I × R (Voltage = Current × Resistance)
A: Dependent variable
100: Define renewable energy.
A: Energy from sources that are naturally replenished at a rate faster than they are used.
200: What is the difference between an energy transfer and an energy transformation?
A: Transfer moves energy between objects; transformation changes it from one form to another.
200: Define a series circuit.
A: A circuit where components are connected in a single path.
200: What is the voltage if resistance = 15Ω and current = 3A?
A: 45V
200: What does a straight-line graph of voltage vs current suggest?
A: The relationship is proportional (Ohm’s Law).
200: Give one advantage of solar energy.
A: It is sustainable and non-polluting.
300: What is the formula for energy efficiency?
A: Efficiency = (Useful energy output ÷ Total energy input) × 100
400: In a series circuit, what happens to the brightness of bulbs when more are added?
A: They get dimmer.
300: What is the current if voltage = 120V and resistance = 10Ω?
A: 12A
300: Use the graph to extrapolate the current for current for voltage 16.
1.20 amps
300: Explain what should be included in the following question: Evaluate the advantages and disadvantages of using renewable and non-renewable sources of energy to generate electricity referring to the data below.
Define renewable and non renewable
Identify a benefit of renewable and non-renewable resources
Identify a limitation of renewable and non-renewable resources
Explains one benefit and/or limitation of renewable with reference to data
Explains one benefit and limitation of non renewable with reference to data
Provides an overall value judgement on renewable and non-renewable resources
400: Which appliance is most energy efficient: Fan (147J/210J), TV (70J/150J), Light bulb (20J/100J), Drill (550J/1500J)?
A: Electric fan – 70% efficiency.
500: What does a voltmeter measure, and how is it connected?
A: It measures voltage and is connected in parallel.
400: Explain the relationship between current and voltage.
A: As voltage increases, current also increases—provided resistance stays the same. This direct relationship is described by Ohm’s Law (V = I × R).
400: What is the resistance if 6V produces 0.6A?
A: 10Ω
400: Explain how an electric generator produces electrical energy.
A magnet is rotated around a coil of wire causing electrons to flow in the wire.
500: Describe a real-life example of energy transformation.
A: In a toaster, electrical energy transforms into heat energy to toast bread.
500: Draw a circuit on the board with two lights that can be turned off separately, voltmeters measuring the voltage of each and an ammeter measuring the current in the whole circuit.
Correctly drawn.
500: A circuit has a voltage of 20 volts and a current of 4 amps.
Use Ohm’s Law to calculate the resistance.
If the resistance stays the same, what would the current be if the voltage increases to 40 volts?
A:
R=5Ω
I=8A
500: What must a graph include?
S - scales even
P - plot points accurate
L - labels with units
A - y axis DV
T - title
500: Provide two benefits and two limitations of using coal to generate electricity.
Benefits:
Coal is relatively cheap to produce and purchase.
Coal power plants can supply a consistent and reliable energy output (baseload power).
Limitations:
Burning coal releases high amounts of carbon emissions (820 kg/MWh), contributing to climate change.
Coal is a non-renewable resource and will eventually run out.