Question

In an experiment of verification of Ohm’s law following observations are obtained.

Potential difference V (in volt)	0.5	1.0	1.5	2.0	2.5
Current I (in ampere)	0.2	0.4	0.6	0.8	1.0

Draw a characteristic V –I graph and use this graph to find:

(a) potential difference V when the current I is 0.5 A,

(b) current I when the potential difference V is 0.75 V,

(c) resistance in circuit.

Answer 1

(a) 1.25 V

(b) 0.3 A

(c) The graph is linear so resistance can be found from any value of the given table. For instance:

When V = 2.5 Volt

Current is I = 1.0 amp

According to ohm's law :

R = V/I

R = 2.5/1.0 = 2.5 ohm

Comments

How the first one i.e. (a) 1.25V came and (b) 0.3 A came

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(a) Potential difference is 1.25V when the current is 0.5A
(b) Current is 0.3A when the potential difference is 0.75V