Uses of electricity

The diagram gives the details printed on an electric kettle. $240\,\text{V}\quad 50\,\text{Hz}$ $600\,\text{W}\quad 700\,\text{cm}^3$ What is the frequency of the electricity supply used to power the kettle?

May/June 2015

Electrical power is carried by cables across long distances at very high voltages. What effects result from using a high voltage transmission system?

May/June 2022

Which electrical appliance operates by using the heating effect of electricity?

May/June 2024

The diagram illustrates the circuit for a hair-dryer. The fan motor is rated at $0.10\,\text{kW}$ and each heater is rated at $0.40\,\text{kW}$. Electricity costs $8.0\,\text{cents/kW h}$. What is the cost of operating the hair-dryer for two hours when switches P and Q are closed and switch R is open?

Oct/Nov 2017

The diagram illustrates the circuit of a hair-dryer. The fan motor is rated at $0.10\,\text{kW}$ and each heater is rated at $0.40\,\text{kW}$. The price of electricity is $8.0\,\text{cents/kW h}$. How much does it cost to operate the hair-dryer for two hours when switches $P$ and $Q$ are closed and switch $R$ is open?

Oct/Nov 2017