CBSE Class 10 Science 2018 · Paper 31/1 · Question 27

Electricity 2 marks Medium

The values of current (

I

) flowing through a given resistor of resistance (

R

), for the corresponding values of potential difference (

V

) across the resistor are as given below : Plot a graph between current (

I

) and potential difference (

V

) and determine the resistance (

R

) of the resistor.

$V$ (volts)	0.5	1.0	1.5	2.0	2.5	3.0	4.0	5.0
$I$ (amperes)	0.1	0.2	0.3	0.4	0.5	0.6	0.8	1.0

Answer

The points lie on a straight line through the origin; its slope gives $R = 5 Ω$ .

Graph: with

I

on the x-axis and

V

on the y-axis, the eight points lie on a straight line passing through the origin (

V \propto I

, Ohm's law). Resistance:

R = slope = \frac{Δ V}{Δ I} = \frac{4.0 - 1.0}{0.8 - 0.2} = \frac{3.0 V}{0.6 A} = 5 Ω

🔒 Step-by-step solution