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

Hint : Use Ohm's law to determine the current.

Step 1 : Make the circuit

Connect the $3$ resistances $R_1$, $R_2$ and $R_3$ in series across a battery with voltage $V$, then connect $3$ voltmeters in parallel to $R_1$, $R_2$ and $R_3$ respectively and $1$ ammeter in series to resistances as shown in the figure.

Step 2 : Take readings of voltmeters and ammeter

Take the readings of voltmeter, let it be $V_1$, $V_2$ and $V_3$

Then take the reading of ammeter, let it be $I$

Step 3 : Use Ohm's law to find current passing through each resistance

Calculate the current passing through each resistance using Ohm's Law.

By Ohm's Law $V=IR$

So $I_1$ = $V_1/R_1$

$I_2$ = $V_2/R_2$

$I_3$ = $V_3/R_3$

Step 4 : Compare the value of current

We will see that $I_1$ = $I_2$ = $I_3$ = $I$

Final step :

Hence it is shown from this experiment that same current flows through every part of the circuit containing $3$ resistances in series.