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WorksheetsEnergy Transfers and Efficiency
Total questions: 10
Worksheet time: 10mins
An open system is...
an object with a hole in it
an object which gains or loses energy
an object which does not let energy in or out
an object that is outside
Almost all objects lose energy in the form of (a) .
Select the correct equation:
Efficiency = wasteduseful×100
Efficiency = usefulwasted×100
Efficiency = inputwasted×100
Efficiency =inputuseful×100
A (a) diagram shows the energy transfers in a system.
What is the value of the wasted energy?
(a)
As a percentage, what is the efficiency of the bulb represented by the Sankey diagram?
(a)
What type of energy is useful?
(a)
Which bulb is the most efficient?
Filament bulb
LED light
CFL lamp
A device transfers 600 J of electrical energy into 350 J of useful sound energy. Calculate the efficiency of the device to 2 significant figures.
(a)
A bulb is 70% efficient. It produces 49 J of light energy. How much energy is inputted?
(a)
