Q. 44.1( 47 Votes )

# The following table shows current in Amperes and potential difference in Volts.

A. Find the average resistance.

B. What will be the nature of the graph between the current and potential difference? (Do not draw a graph.)

C. Which law will the graph prove?

Answer :

A. According to the equation V = IR

R = V/I

Resistance in the 1st case R_{1} = V_{1}/I_{1}

= 4/9

= 0.444 Ω

Resistance in the 2nd case R_{2} = V_{2}/I_{2}

= 5/11.25

= 0.444 Ω

Resistance in the 3rd case R_{3} = V_{3}/I_{3}

= 6/13.5

= 0.444 Ω

Average resistance R_{avg} =

= (0.444 + 0.444 + 0444)/3

= 0.444 Ω

B. In this case as R is constant, we can observe the increase in I as V increases.

We know that V = IR .

It represents a straight line starting from origin with a slope R. Therefore, the nature of graph between current and potential difference will be a straight line.

The graph is given below:

C. The graph proves Ohm's law.

According to Ohm's law the current passing through a conductor between two points is directly proportional to the voltage across the two points.

I∝V

I = V/R

Rate this question :