Current electricity

2. Presented by : Menahil ahmed (2861)
Hafsa Javed (2911)
Madiha Rehman (3024)
Shahab Khan (2859)

3. Ohm’s Law:
“The amount of current passing through a conductor is
directly proportional to the potential difference applied across its ends,
provides the temperature & physical state of the conductor remains
same”.
Formula:-
V=IR
 I= Current
 V= Voltage
 R= Resistance

4. Resistance:
“The property of a substance which offers opposition to the
flow of current through it is called its resistance”.
Unit:
Unit of resistance is ohm.
Factors affecting Resistance:
1. Length.
2. Cross-sectional area.
3. Material.
4. Temperature.

5. Voltage:
“It is the electrical pressure that pushes or pulls charges”.
Unit:
Volts ( V ).
Circuit:
A close conducting path.
Unit:
Amperes ( A ).

6. Chemical effect of current
Electrolytic Conduction
Electrolysis
Ionization

7. Types of current:
AC
(Alternating Current)
DC
(Direct Current)
 Electric current which
periodically reverses direction.
The unidirectional flow of
an electric charge.

8. Cell
“ A device that delivers electric current as a result of a chemical
reaction”.
Types of Cells:
 Electrolytic cells.
 Photovoltaic cells.
 Fuel Cells.
Construction:
 Cathode.
 Anode.
 Separator.

9. Battery
“A device consisting of one or more cells with external
connections”.

10. Combination of the cell:
In series:-
o The negative terminal of the cell is connected to positive terminal of
next one.
o The voltage is increased.
In Parallel:-
o All the positive terminals are connected together and the negative
terminals are connected together.
o The voltage remains the same.