To find the relationship between voltage, current, and resistance in acircuit.

1. Experiment no:01
Name of Experiment :Study of ohm’s law .
Objectives:
 To verify Ohm’s law experimentally.
 To find the relationship between voltage, current, and resistance
in a circuit.
Circuit diagram:
Fig:A simple resistivecircuit to verify Ohm’s law.
Theory :
Ohm’s law states that “the voltage v (or potential difference) across a
resistor is directly proportional to the current i flowing through it.” As the current
increases the voltage drop also increases provided that the resistance is kept
constant; and the current decreases as the resistance increases provided that the
voltage across the resistor terminals remains the same. Mathematically,
v  i
v = iR
where R is the constant of proportionality and is the resistance of the resistor
element.

2. Material that obeys Ohm's Law is called "ohmic" or "linear" because the
potential difference (or voltage) across its terminals varies linearly with the value
of current flowing through it.
Required Equipments :
 Resistors.
 Ameter and voltmeter.
 Variable DC power supply.
 bread-board and
 connecting wires.
Data Table :
Serial No V (volt) I (mAmp) R (Ω)
01 05 30 166
02 30 180 166
03 10 60 166
04 15 90 166
05 20 120 166
06 25 150 166
07 07 42 166
Fig: Data table of ohm’s law.
Result &Discussion:
By observing the observation table, it is proved that the ratio
of potential difference and current is constant .Thus, potential difference at the
ends of the conductor is directly proportional to the current flowing through it.
Thus, ohm’s law is verified by this experiment.
The relation between the V and I is that they both are directly proportional to
each other. Thus keeping the resistance constant, if Voltage in the circuit
increases, Current increases too and vice versa. The relation between the I and R
is that they both are Inversely proportional to each other. Thus keeping the

3. Voltage constant, if Resistance in the circuit increases, Current decreases and vice
versa.
PRECAUTIONS:
1) All the connection should be tight.
2) Ammeter is always connected in series in the circuit while voltmeter is parallel
to the conductor.
3) The electrical current should not flow the circuit for long time, Otherwise its
temperature will increase and the result will be affected.