Power of Electricity Appliances Flashcards
Electricity (15 cards)
What transfers energy in a circuit?
A moving charge transfers energy
This occurs because the charge does work against the resistance of the circuit.
How do electrical appliances transfer energy?
They transfer energy to components in the circuit when a current flows.
What type of energy do kettles transfer from the mains supply?
Thermal energy to the heating element.
What is the relationship between current and energy transfer?
Higher current leads to more energy transferred to thermal energy stores.
How is the efficiency of an electrical appliance calculated?
Efficiency = Useful energy output / Total energy input.
What factors determine the total energy transferred by an appliance?
Time the appliance is on and its power.
What is the definition of power in relation to an appliance?
The energy transferred per second.
Fill in the blank: Energy transferred (J) = _______ (W) x Time (s)
Power
Calculate the energy transferred by a 600 W microwave used for 5 minutes.
180,000 J
If a 600 W microwave transfers 180,000 J, how long (in seconds) would a 750 W microwave take to do the same work?
240 s
Convert 240 seconds to minutes.
4 minutes
What does the power rating of an appliance indicate?
The maximum amount of energy transferred per second.
How does the power rating help customers?
It helps customers choose between models based on electricity usage.
True or False: A higher power rating always means an appliance is more efficient.
False
What can be said about an appliance that is more powerful but less efficient?
It might transfer the same amount of energy or even less to useful stores.
