Activity 12.5 Class 10 Science Electricity
Activity 12.5 asks us to measure the potential difference at various positions when resistances are in series.
Observation:
The potential difference across different resistances in series have different values.
Explanation:
Potential difference is the form of energy similar to the potential energy of an object due to gravitational pull. In kinetics, if we drop an object from a height, its potential energy decreases. Similar things happen here too; here electron travel from one terminal of the battery to another terminal due to the P.D. During this travelling, the PD decrease from place to place.
Calculation:
Current in a closed circuit is same,
Now, as per Ohm’s law, V=IR
V1= I*R1; V2=I*R2; and V3= I*R3
i.e. V1+V2+V3= I*(R1+R2+R3)
And V= I*(R1+R2+R3)
From the above two equations, we find that
V = V1+V2+V3
Inference/conclusion:
Potential different at different positions in a circuit is different, and their sum equals the potential difference at the source.
