EXPERIMENT NO.3-M
OHM’S LAW
OBJECTIVES:
1. To be familiar with Ohm’s Law.
2. To study the sign conversions as regard to voltage and current.
DISCUSSION:
For most materials and under fixed environmental conditions, the
current in its directly proportional to the potential difference across it. The
proportionality constant is the resistance of the material. This relationship
is known as Ohm’s Law. In equation form, we write
V = IR
Ohm’s Law is applicable whether we are dealing with simple circuit or
with parts of a more complex circuit. The resistance used in the equation
could be that of a single resistor or the equivalent resistance of a group of
resistors. In using Ohm’s law, we should be consistent as regard the
quantities used in the equation.
A current Iab is positive if it is directed from the point a to a point b.
we could easily establish this direction by using an ammeter. A
conventional ammeter would have an uphill deflection if the current enters
its positive terminal and leaves its negative terminal. A potential difference
Vab is positive if point a is at a higher potential than point b. again, this
could be easily be establish using a voltmeter. A conventional voltmeter will
have an uphill deflection if its positive terminal is maintained at a higher
potential.
INSTRUMENT AND COMPONENTS:
VOM
