Question

A storage battery of emf 8V & intrnal resistance 0.5 ohm is being charged by a 120V d.c..Supply using a series resistor of 15.5 ohm.What is the terminal voltage of the battery during charging? What is the purpose of having a series resistor in the charging circuit.

Answer 1

Answer in in the attachment

Answer 2

Hey !!

(i) 3ε = 6 ; ε = 2

(ii) For power to be maximum in the circuit the load resistance will be equal to internal resistance of circuit.

  Let r is the internal resistance of one cell then,

          V = 3E + 3Ir

when, V = 0.1 = 2A , so r = E/I

                          = 1Ω

So for maximum power dissipation ( ∴ r = R )

R = 3R = 3Ω

For maximum power dissipation  

  I = 3E / R + 3R

    = 3 × 2 / 3 + 3

FINAL RESULT = 11.5 volt

HOPE IT HELPS YOU !!