A storage battery of emf 12 V and internal resistance 0.5 ohm is to be charged by a 120V d.c. supply of negligible internal resistance.What resistance is required in the circuit for the charging current to be 3A? What is the terminal voltage of the battery during charging?

Open in App

Solution

Applying Kirchoff voltage rule we get
net emf = (120-12)=117 V , net resistance =( R+r) and net current =3A
now 117=i xR_net
117/3 =r+R
39-0.5 =R=38.5 $Ω$
and now use the formula of terminal voltage =E- ir
=12-3x0.5=12-1.5=10.5 volt.

Suggest Corrections

Similar questions

Q. A storage battery of emf 8.0 V and internal resistance 0.5 W is beingcharged by a 120 V dc supply using a series resistor of 15.5 W. Whatis the terminal voltage of the battery during charging? What is thepurpose of having a series resistor in the charging circuit?

A storage battery of emf 8.0 V and internal resistance 0.5 Ω is being charged by a 120 V dc supply using a series resistor of 15.5 Ω. What is the terminal voltage of the battery during charging? What is the purpose of having a series resistor in the charging circuit?

A storage battery of emf $8.0 V$ and internal resistance $0.5 Ω$ is being charged by a $120 V$ dc supply using a series resistor of $15.5 Ω$ . What is the terminal voltage of the battery during charging? What is the purpose of having a series resistor in the charging circuit?

The emf of a storage battery is 90 V before charging and 100 V after charging by a direct current voltage supply. When charging began the current was 10 A. What is the current at the end of charging if the internal resistance of the storage battery during the whole process of charging may be taken as constant and equal to 2 ohms?

Q. When a battery of emf

8 V

with internal resistance

0.5 Ω

is charged by a

120 V

DC supply using a series resistance of

15.5 Ω

, then the terminal voltage of the battery is :

Join BYJU'S Learning Program

A storage battery of emf 12 V and internal resistance 0.5 ohm is to be charged by a 120V d.c. supply of negligible internal resistance.What resistance is required in the circuit for the charging current to be 3A? What is the terminal voltage of the battery during charging?

Applying Kirchoff voltage rule we get net emf = (120-12)=117 V , net resistance =( R+r) and net current =3A ​now 117=i xRnet 117/3 =r+R 39-0.5 =R=38.5 Ω and now use the formula of terminal voltage =E- ir ​ =12-3x0.5=12-1.5=10.5 volt.

Applying Kirchoff voltage rule we get
net emf = (120-12)=117 V , net resistance =( R+r) and net current =3A
now 117=i xR_net
117/3 =r+R
39-0.5 =R=38.5 $Ω$
and now use the formula of terminal voltage =E- ir
=12-3x0.5=12-1.5=10.5 volt.