Electricity 


7.1  Electricity                
 
ENERGY
  • Energy means the ability to do work
  • The S.I.unit for energy is joule (J)

Forms of energy
  1. Sound energy
  2. Kinetic energy
  3. Electrical energy
  4. Gravitational potential energy
  5. Elastic potential energy
  6. Light energy
  7. Nuclear energy
  8. Heat energy
  9. Chemical energy

Sources of energy
  1. The Sun
  2. Geothermal
  3. Water
  4. Biomass
  5. Fossil fuel
  6. Radioactive substances
  7. Wave
  8. Wind

Electrostatic Charges
 
  • Electric charges consist of positive charges and negative charges
  • The repulsion among these charges are called electrostatic forces 
  • Electroscope is used to detect the existence of electric charges on an object

Electric current
\(\downarrow\)
Electric current can be defined as the rate of flow of electric charges through a conductor

Current, Voltage and Resistance
 
  • S.I unit for electric current is ampere(A) - measured by ammeter
  • The voltage is the potential difference between two points, volt(V) - measured by voltmeter
  • The unit for measuring resistance is ohm (Ω)
  • The relationship between current, voltage and resistance is Ohm's Law
\(V=IR\)

 

Electricity 


7.1  Electricity                
 
ENERGY
  • Energy means the ability to do work
  • The S.I.unit for energy is joule (J)

Forms of energy
  1. Sound energy
  2. Kinetic energy
  3. Electrical energy
  4. Gravitational potential energy
  5. Elastic potential energy
  6. Light energy
  7. Nuclear energy
  8. Heat energy
  9. Chemical energy

Sources of energy
  1. The Sun
  2. Geothermal
  3. Water
  4. Biomass
  5. Fossil fuel
  6. Radioactive substances
  7. Wave
  8. Wind

Electrostatic Charges
 
  • Electric charges consist of positive charges and negative charges
  • The repulsion among these charges are called electrostatic forces 
  • Electroscope is used to detect the existence of electric charges on an object

Electric current
\(\downarrow\)
Electric current can be defined as the rate of flow of electric charges through a conductor

Current, Voltage and Resistance
 
  • S.I unit for electric current is ampere(A) - measured by ammeter
  • The voltage is the potential difference between two points, volt(V) - measured by voltmeter
  • The unit for measuring resistance is ohm (Ω)
  • The relationship between current, voltage and resistance is Ohm's Law
\(V=IR\)