Question

When switch S in the figure is open, the voltmeter V of the battery reads 3.06 V. When the switch is closed, the voltmeter reading drops to 2.96 V, and the ammeter A reads 1.6 A. Find the internal resistance of the battery. Assume that the two meters are ideal, so they don't affect the circuit. (Give your answer in decimal with 3 digits after the decimal point using Ohm (Ω) as unit)

Answer 1

Given

Open circuit voltmeter reading is V =3.06 V

Closed circuit voltmeter reading V' =2.96 V

Part a )

Emf of battery = Open circuit voltameter reading

=3.06 V

part b )

The terminal voltage is

Vt=E-Ir

r =E-Vt/I

=3.06V - 2.96 V / (1.6A)

= 0.0625 ohm

Part c )

The current in the circuit is

I = E / R+r

R+r = E/I

R=(E/I ) - r

R=(3.06 V / 1.6A) -(0.0625)

R=1.85 ohm

I hope help you !!