Efficiency (Edexcel GCSE Physics Combined Science): Quizzes
📚Quizzes
Practise the questions
12 questions from this quiz
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Practise the questions
12 questions from this quiz
What does efficiency measure in a device?
What does efficiency measure in a device?
How well input energy converts to useful
Which statement describes a highly efficient device?
Which statement describes a highly efficient device?
It wastes little energy
What is the formula for calculating efficiency?
What is the formula for calculating efficiency?
A device receives 200 J and transfers 150 J usefully. What is its efficiency?
A device receives 200 J and transfers 150 J usefully. What is its efficiency?
75%
What is the maximum possible efficiency of any device?
What is the maximum possible efficiency of any device?
Less than 100%
Why can no device be more than 100% efficient?
Why can no device be more than 100% efficient?
Energy cannot be created
Which forms can wasted energy take?
Which forms can wasted energy take?
Heat or sound
Where does wasted energy typically go?
Where does wasted energy typically go?
To thermal energy stores in surroundings
How does lubrication improve efficiency?
How does lubrication improve efficiency?
It reduces friction between moving parts
Which method reduces air resistance to improve efficiency?
Which method reduces air resistance to improve efficiency?
Streamlining shapes
Which equation represents the conservation of energy principle?
Which equation represents the conservation of energy principle?
Total Energy = Useful Output + Wasted
What happens when mechanical work is done against friction?
What happens when mechanical work is done against friction?
Wasted heat is created