Two cells of same emf E but internal resistance r1 and r2 are connected in series to an external resistor R (figure).
Two cells of same emf E but internal resistance r1 and r2 are connected in series to an external resistor R (figure). What should be the value of R so that the potential difference across the terminals of the first cell becomes zero ?
Answers
In this solution first we apply Ohm's law to find current in the circuit .,Effective emf of two cells = E + E = 2E,Effective resistance = R + r,1, + r,2, ,So the electric current is given by,I = E + E / R + r,1 ,+ r,2 ,The potential difference across the terminals of the cell and putting it equal to zero. ,how net emf is 2E, it should be ZERO as they are connected with like poles in series.