EXPERIMENTAL VERIFICATION OF OHM'S LAW

 EXPERIMENTAL VERIFICATION OF OHM'S LAW

OBJECTIVE:-  Verification of ohm's law 

EQUIPMENT REQUIRED :- A battery, an ammeter, voltmeter, rheostat, plug key, coil, of unknown substance, connecting wire etc. 

THEORY :- Ohm's law deal with the relationship between voltage (p.d) and current in an ideal conductor. 

This relationship states that - 

The p. d.(voltage) across an ideal conductor is directly proportional the current through it. 

Ohm's law given by 

V=IR

Where, 

V= potential difference 

I= current 

R= constant (Resistance) 

CIRCUIT DIAGRAM :- 

PROCEDURE:-

1. The circuit is connected as per the circuit diagram.

2. The plug key is inserted and the rheostat is adjusted so that a definite amount of current (I) flows in the circuit. This value of current is recorded.

3. As the current flows through the unknown resistance a p. d. is developed which is read from voltmeter.

4. The procedure is again adjusted to a different value of current (I) and the corresponding voltage values are noted down.

5. This procedure is repeated for at least 5-6 current reading and for voltage also.

6. A tabular column is drown and the reading of I and v are tabulated. 

7. Graph of V-I is down. A straight line is obtained.

V=IR which proves Ohm's law.

8. The slope of the graph is found out the slope gives the resistance (R) of the unknown resistance.

Observation table - 

PRECAUTIONS :-  

➡️All the connection must be tight. 

➡️Record the current at the regular interval of voltage. 

➡️We should connect ammeter in series and voltmeter in parallel. 

➡️While changing the voltage, rheostat must be move in one direction only. 

➡️Lest count of voltmeter and ammeter must be properly calculated. 

➡️Do not pass a large current through the resistance. 

➡️While measuring the voltage and current the needle of meters should not move out of the scale.