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?
Given: A battery of emf 10V and internal resistance 3Ω is connected to a resistor. The current in the circuit is 0.5A To find the terminal voltage of the battery when the circuit is closed Solution: Emf of the battery, E=10V Internal resistance of the battery, r=3Ω Current in the circuit, I=0.5A Resistance of the resistor = R The relation for current using Ohm's law is, I=R+rE⟹R+r=IE⟹R+r=0.510⟹R=20−3=17Ω Terminal voltage of the resistor = V According to Ohm's Law, V=IR⟹V=0.5×17⟹V=8.5V Therefore, the resistance of the resistor is 17Ω and the terminal voltage is 8.5V
