Usage of Electric Energy

• Electric Power


  the rate, per unit time, at which electrical energy is transferred by an electric circuit.
• Formula for Electric Power

  $P=$$VI$

  • A variation can be obtained using ohm’s law that would involve the internal resistance or R of the equipment that converts electric energy. (Power lost due to resistance.

  $P=$$\frac{V^2}{R}$
• Electric Power


  uses Watts as unit or W
• The formula for Heat generation rate


  $heat\hspace{1mm}generation\hspace{1mm}rate=$$I^2R$

  $Resistance=$$\frac{V^2}{P}$
• 0.001 A


  causes mild tingling sensation in body
• 0.01 to 0.19 A


  Causes Muscle spasms
• 0.2 A


  Causes heart fibrillation
• higher than 0.2 A


  causes heart to stop beating
• Circuits


  provide the pathway from the source of the electrical energy to where it needs to be converted to different forms.
• Fuse


  Burns out if there is an excessive amount of current
• Fuse


  designed to have very thin pieces of wire which only allow a specific amount of current otherwise it will burn
• Magnetism


  occurs because of the alignment of atoms
• Magnetic Domains


  aligned atoms
• Magnetic Force


  attraction and repulsion which exists between magnetic poles
• Magnetic Poles


  North pole and South pole
• Magnetic Field


  region where magnetic interaction can be experienced
• Magnetic field lines


  graphical representation of magnetic fields