# Activity 12.5 Class 10 Science Electricity

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.

Next: Experiment to demonstrate resistors in parallel have different current flowing through them; Activity 12.6.

See also: Experiment to demonstrate current in a closed circuit remains the same all places; Activity 12.4.