Question

The adjacent plot shows variation of the terminal potential difference (V) of a cell as a function of current (I) drawn from it. Using the plot determine (1) the emf and (2) internal resistance of the cell ​

Answer 1

Answer:

Given, PD=v,current=I

Since V=E−ir⇒0.4=E−0.04r⇒E=0.4+0.20r...1

Similarly, E=0.8+0.12R....2

From equation 1 and 2 we get,

0.4+0.20r=0.8+0.12r⇒0.08r=0.4⇒r=40Ω

Now,

E=0.4+0.20×5=0.4+1=1.4volt