Question

A cell of emf e & and internal resistance r is connected with external resistance R. The between terminal voltage V and current I is ?​

Answer 1

Answer:

Here the terminal voltage , V=E−ir...(1) and the current i=E/(R+r)

Now, V=E−

(R+r)

E

r=

R+r

ER

=

(1+r/R)

E

=...(2)

According to equation (1) and (2), the graph V vs i and V vs R will be as shown in figure.

As i=E/(R+r) so 1=E/(4+r) or E=4+r...(3) and

0.5=E/(9+r) or 2E=9+r....(4)

using (3), 2(4+r)=9+r or r=1Ω

Thus, E=4+1=5V