The graph shown here shows the variation of terminal potential differe

1.	The graph shown here shows the variation of terminal potential difference V, across a combination of three cells in series to a resistor, versus current i:(i) Calculate the emf of each cell.(ii) For what current i, will the power dissipation of the circuit be maximum?
Answer» (i) Let ε be emf and r the internal resistance of each cell. The equation of terminal potential difference V = ε_eff– i r_intbecomes V = 3ε –i r_int …(i) Where r_int is effective (total) internal resistance. From fig., when i = 0, V = 6.0 V ∴ From (i), 6 = 3ε - 0 \(\Rightarrow \epsilon=\frac{6}{3}=2V\) i.e., emf of each cell, ε = 2 V Thus, emf of each cell, ε = 2V

The graph shown here shows the variation of terminal potential difference V, across a combination of three cells in series to a resistor, versus current i:(i) Calculate the emf of each cell.(ii) For what current i, will the power dissipation of the circuit be maximum?

Answer»

(i) Let ε be emf and r the internal resistance of each cell. The equation of terminal potential difference

V = ε_eff– i r_intbecomes

V = 3ε –i r_int …(i)

Where r_int is effective (total) internal resistance.

From fig., when i = 0, V = 6.0 V

∴ From (i), 6 = 3ε - 0 \(\Rightarrow \epsilon=\frac{6}{3}=2V\)

i.e., emf of each cell, ε = 2 V

Thus, emf of each cell, ε = 2V