#### Question

A battery of emf 10 V and internal resistance 3 Ω is connected to a resistor. If the current in the circuit is 0.5 A, what is the resistance of the resistor? What is the terminal voltage of the battery when the circuit is closed?

#### Solution

Emf of the battery, *E* = 10 V

Internal resistance of the battery, *r* = 3 Ω

Current in the circuit, *I* = 0.5 A

Resistance of the resistor = *R*

The relation for current using Ohm’s law is,

`I=E/(R+r)`

`(R+r)=E/I`

`=10/0.5=20Omega`

`therefore R=20-3=17Omega`

Terminal voltage of the resistor = *V*

According to Ohm’s law,

*V* = *IR*

= 0.5 × 17

= 8.5 V

Therefore, the resistance of the resistor is 17 Ω and the terminal voltage is

8.5 V.

Is there an error in this question or solution?

Solution A Battery of Emf 10 V and Internal Resistance 3 Ω is Connected to a Resistor. If the Current in the Circuit is 0.5 A, What is the Resistance of the Resistor? What is the Terminal Voltage of the Battery When the Circuit is Closed? Concept: Cells, Emf, Internal Resistance.