CBSE Notes, Lectures

CBSE - Physics - Electricity

Electricity

NCERT Exercise

The values of current I flowing in a given resistor for the corresponding values of potential difference V across the resistor are given below −

I (amperes ) 0.5 1.0 2.0 3.0 4.0
V (volts) 1.6 3.4 6.7 3.0 13.2

Plot a graph between V and I and calculate the resistance of that resistor.

The plot between voltage and current is called IV characteristic. The voltage is plotted on x-axis and current is plotted on y-axis. The values of the current for different values of the voltage are shown in the given table.

V (volts) 1.6 3.4 6.7 3.0 13.2
I (amperes ) 0.5 1.0 2.0 3.0 4.0

The IV characteristic of the given resistor is plotted in the following figure.

 

The slope of the line gives the value of resistance (R) as,

Slope = 1/R = BC/AC = 2/6.8

R= 6.8/2 = 3.4 Ω

Therefore, the resistance of the resistor is 3.4 Ω.

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