Question

How will you infer with the help of an experiment that the same current flows through every part of the circuit containing three resistances in series connected to a battery?

Answer 1

Step 1: Construction of circuit

1. Connecting three resistances R₁, R₂, and R₃ in series combination across the battery of voltage V.
2. Adding an ammeter in series and a voltmeter in parallel combination in the circuit.

Step 2: Circuit diagram

Step 3: Observation

1. Take the reading of the potential difference between R₂ and R₃ in the absence of R₁.
2. Take the reading of the potential difference between R₁ and R₃ in the absence of R₂.
3. In each case, the ammeter reading is the same. i.e, current remains the same in the circuit.

Step 4: Calculation

1. From the concept of Ohm's law, we know that, V = IR, where V = voltage, I = current, and R = resistance.
2. The current in terms of voltage and resistance of each resistor is $I=\frac{V}{R}$.
3. From the observation, the ratio of voltage and potential is same. thus, the current flowing in the circuit is the same.

Therefore, in the series combination of resistance, the current flow in the circuit is constant.