D.C Theory

D.C Theory

1. principles of electricity

   • electrons flow from negative to positive
     • In conventional current flow current flows from positive to negative
       • protons are always in the center of an atom, electrons are outside.
         • when a electron joins a atom with protons the electron then becomes a negative ion.

2. ohms law

   • I=current
     • R=Resistance
       • V=Voltage
         • V=IR

3. Electromagnetic induction

   • electrochemistry
     • photoelectric effect
       • thermoelectric effect
         • piezoelectric

4. effects of electric current

   • thermal
     • chemical
     • magnetic

5. SI units

   • area =A - square meter- m2
     • resistivity=p - ohm meter - ohm m
   • capacitance=C - farad- F
     • reactance=X - ohm
       • power=P - watts - W
         • potential difference=V - volts - V
         • magnetic flux density=B - tesla - T
           • Inductance=L - henry - H
             • force=F - newton - N
           • Impedance=Z - ohm
             • frequency=f - hertz - Hz
               • charge- Q - coulomb - C