Question

How much electrical energy is used by a 1000-watt microwave that runs for 30 minutes?

Answer 1

Hint: Electrical energy is the product of power and time consumed. To calculate energy we should know the power of the object in watts and the time consumed in seconds to calculate the electrical energy in watts per seconds that is joules $ (J) $ .

Complete step by step answer:
We know that the formula used to calculate energy is :
 $ E = P \times t $ $ $
Where $ E $ is the electrical energy, $ P $ is the power and $ t $ is the time consumed by the object.
It is given in the question that
 $ P = 1000watt \\
  t = 30\min \\ $
We should now convert these quantities into their standard forms to calculate the energy in joules.
 $ P = 1000watt \\
  t = 30\min = 30 \times 60 = 1800\sec \\ $
Now, we substitute these values into to the equation,
 $ E = P \times t \\
  E = 1000 \times 1800 \\
  E = 1800000J \\
  E = 1.8MJ \\ $
Where $ M $ is megajoule.
 $ 1MJ = {10^6}J $
Hence, $ 1.8MJ $ electrical energy is used by a 1000-watt microwave to work for 30 minutes.

Note:
Electrical Energy is the potential or kinetic energy created by the movement of charged particles. It is the energy created when the electrons move from one point to the other. Electrical energy can also be converted into various other forms of energy like heat, light and other mechanical energy. The major application of electrical energy is the working of home appliances like bulb, fan, microwave etc.