Fri May 25, 2012 By: Namami Gaur

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.

Expert Reply
Fri May 25, 2012
Resistance of the circuit = 15.5 + 0.5 = 16 ohms
Current = 8/16 = 0.5 ampere
the terminal voltage of the battery will be the same as the voltage across the 15.5 Ohms load
Using ohms law again

V = I x R
V = 15.5 x 0.5  = 7.75 V
This is the terminal voltage.
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