17:- Ohm’s law 
Aim :- to learn about Ohm ‘ s law.
Requirement :- holder , wire ,switch ,cutter ,plier .
Procedure :- first connected a wire to switch and other end connected to the holder . second
Wire connected in holder and other end to the board and checked that by one switch one
Lamp is connected the current rate increased and the voltage remains the same.
Ohm’s law :-  it states that
                      V = I
Means voltage is always propertional to current.
I =current
V= voltage
R= Resistance
It can also be written as
 V = IR
  I = v/r
  R= v/r
By this we can find all three :-
1) Voltage
2) Current
3) Resistance.
For example :- 1) v= 6.7 , I= 0.01
as per formula
R= v/i
V .= ir
R=v/I
R= 6.7/0.01
R=670 ohm.
2)  I/rr= 1/r1 + 1/r2
           = 0.1 + 0.1
           = 0.2 ohm