P1.3 The Usefulness of Electrical Appliances Flashcards
What are electrical appliances designed to do?
To transfer electrical energy into other forms
What is the power of an appliance?
The amount of energy transferred in a give time - given in watts
What is the equation for finding the energy transferred of an appliance using power?
E = P x t –> Energy transferred (J) = Power (W) x time (s)
What is a kilowatt-hour?
The amount of energy used by a 1 kW appliance left on for 1 hour
What is the equation for finding the LARGE amount of energy transferred of an appliance using power?
E = P x t –> Energy transferred (kWh) = Power (kW) x time (h)
What is the equation for finding the cost of electricity?
cost of electricity = number of kWh used x price per kWh
What is used in the home to measure how much energy is being used?
An electricity meter
In the exam you may be asked to compare two different appliance e.g. compare battery radios and clockwork radios…
- Battery/clockwork radios are both good in areas with no mains electricity supply
- Batteries can be expensive
- It can get annoying having to wind the clockwork radio
- B’radios are only good if you can get new batteries
- C’radios are better for the environment as energy is needed to make batteries
How does access to electricity make people safer?
Improves safety as electrical energy is turned into light energy, which is safer in the night
How does access to electricity make people healthier?
Refrigeration keeps food cold and vaccines cold, electricity can be used in hospitals for things like x-rays
How does access to electricity keep families close?
Communication - without electricity there would be no internet or phones
