Energy
Give 3 examples of renewable energy
This is the unit of electric power
Why can liquids flow but solids cannot?
Liquid particles have more energy and weaker forces between them
What is the name of the component that provides electrical energy in a circuit?
Battery (or Cell)
What is stored energy?
Potential Energy
Voltage Divided by Resistance
or
Power Divided by Voltage
or
Charge Divided by Time
The more energetic molecules of a liquid are escaping from its surface, causing the liquid to cool. What is happening to the liquid?
Evaporating
How do you decide what fuse to use for an appliance?
A little higher than the current of the appliance
Give one disadvantage of using biomass.
More expensive
If a 12V battery powers a device drawing 2A, what is the power used?
24W
What happens when a gas is compressed into a smaller volume?
The particles hit the container walls more often, increasing pressure
In a parallel circuit, what happens to the total current when you add another branch with a bulb?
The total current increases because there is an additional path for the current.
What is energy that comes from heat inside the Earth?
Geothermal energy
Why do they increase the voltage when transport electricity?
During the flat parts of a heating curve, the temperature stays constant because?
Energy is used to change the state by breaking intermolecular forces
A circuit has a 12V battery and two resistors (6Ω and 3Ω) in series. What is the current in the circuit?
Total resistance = 6 + 3 = 9Ω
Current = V ÷ R = 12 ÷ 9 = 1.33 A (approx)
A 4kg object is lifted to a height of 5 meters. Using g=10m/s^2, calculate its gravitational potential energy.
200J
A 900W oven operates for 2 minutes. How much energy is transferred by the oven?
1.8KJ
Why does evaporation cause a liquid to cool down?
Faster particles escape, lowering average kinetic energy
Explain why a bulb connected in parallel with another bulb will stay lit even if the other one burns out.
Because each bulb has its own separate path for the current, so one bulb does not affect the other's circuit.