Electricity - Mains Electricity

Question 1

Why does a current in a resistor result in the transfer of energy and increase in temperature

Answer 1

The free electrons collide with ions of the metal as they pass through the conductor.

As a result, the free electrons lose electrical energy and the metal ions gain energy.

This causes them to vibrate faster and with bigger amplitude – which means a higher temperature

Question 2

How can the heating effect of an electric current and resistance be used in a variety of domestic contexts

Answer 2

Some components are designed to have a high resistance to make sure this happens, for example electrical heaters that have lots of resistors to ensure a high resistance so a lot of heat is produced.

Question 3

What is the relationship between power, current and voltage

Answer 3

power = current x voltage
P = I x V

Question 4

What is the relationship between voltage, energy transferred, time and current

Answer 4

energy transferred =
current x voltage x time
E = I x V x t