Ohm's Law Lab activity Class 10

VERIFYING OHM’S LAW 

Aim: To prove the ratio of V and I is constant for ohmic conductor. 

Material required: 1.5V batteries-5, Ammeter, Voltmeter, connectors (copper wires), 1 m iron wire (25 gauge) and switch. 

 Ohm’s law: At the constant temperature the potential difference between two ends of a conductor is directly proportional to current flow in it. 

Procedure: 

 1) We connect resistor, switch & ammeter in series and connect volt meter in parallel in the circuit. 

2) Switch on the circuit and observe the readings of ammeter and volt meter. Note the values in the table.

3) Now we connect two batteries instead of one battery in series. We observe the values of V and I and note in the table. 

4) We do the experiment with change the batteries as 3, 4 and 5 respectively. And note the corresponding values of V and I in the table.

5) In all cases we notice that the value of V/I is constant.   

Table:

From the above table we know that the value of V/I is constant and is approximately equal to 0.59 Ω . 

Observations:

1) We observe that in all cases the value of V/I is constant. 

 2) If we take the values of V in x-axis and the values of I in y-axis and draw the graph with V and I values in the table, we observe that the graph looks like a straight line. 

Result: 

1) For ohmic conductors the value of V/I is constant. The ratio of potential difference and current is called resistance. 

2) The conductors which obey the ohm’s law are called ohmic conductors or linear conductors. The V and I graph of the ohmic conductors is a straight line. 

Precautions: 

1. We do the experiment at constant temperature. 

2. We connect the ammeter in series and volt meter in parallel in the circuit. 

 3. We take the readings of V and I without parallax error.