Question

Stale Ohm’s Law. 

Diagrammatically illustrate how you would connect a key, a battery, a voltmeter, an ammeter, an unknown resistance R and a rheostat so that it can be used to verify the above law?

Answer 1

Ohm’s law states that current flowing in a conductor is directly proportional to the potential difference across its ends provided the physical conditions remains constant. 

I ∝ V or V = IR 

Verification of Ohm’s Law: Use the circuit as shown taking case the +ve of voltmeter and +ve of Ammeter should be connected to the +ve of battery and voltmeter in parallel key is closed and Rheostat is set to get the minimum reading in Ammeter and voltmeter. The rheostat is then gradually moved and each time value of A and V are noted. The ratio of v/I is always found constant. This verified ohm’s law.