A battery of emf 8V and internal resistance r=0 5 ohm is being charged by a 120V D C supply - Physics - Current Electricity

Question

A battery of emf 8V and internal resistance r=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 battery during charging?

Somnath physics · Accepted Answer

The internal resistance r = 0 5
Î© and the resistor R = 15 5 Î© are in series
with the DC supply of 120 V

The equivalent resistance of the
charging circuit is, R = 0 5 + 15 5 = 16 Î©

So, the current through the system
due to the charger is, (I = V/R) = 120/16 = 7 5 A

Also, the current due to the 8 V
battery is = 8/16 = 0 5 A (this current is opposite to the current
due to the charger)

Thus, the net current flowing in
the circuit is = 7 5 - 5 = 7 A

The voltage across the internal
resistance is = 7 Ã— 0 5 = 3 5 V

So, the voltage across the
terminals of the battery is = 8 V + 3 5 V = 11 5 V

A battery of emf 8V and internal resistance r=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 battery during charging?