Activity 12.2 Class 10 Science Chapter 12 Electricity
Activity 12.2 asks us to measure the current flowing through different conductive objects.
Observation:
Current through different materials are different.
Explanation:
An object may offer varying degrees of electrical conductance. It depends on their elemental and molecular properties. Some elements like silver, copper, aluminium have high conductivity while others like carbon, rubber do not conduct electricity. We call this property as resistance.
Here we use three different material namely nichrome wire, a torch bulb and a 10W bulb. Nichrome is an alloy of nickel and chromium. It offers high resistance to electrical conductivity. Filament bulb uses tungsten. Tungsten is a high resistance metal which glows at high temperature.
As per Ohm’s law,
V=IR
Since V is constant here, Current ‘I’ becomes inversely proportional to the resistance of the material.
Inference/conclusion:
This experiment demonstrates different material have different electrical conductance or resistance.
See also: Demonstration of Ohms’ law, activity 12.1.
