Take two thin nichrome wires of equal length and different thickness (approximately one of these wire thickness to be double of the other, say 0.3 mm and 0.6 mm). Connect them one by one in a circuit which has a switch and a cell, and allow the current to flow for 30 s in each case. Momentarily touch these wires. Which wire heats up more? Now repeat the same activity with two nichrome wires of same diameter but of different lengths. Prepare a brief report of your activity.
For wires of equal length but different thickness, the thinner wire (0.3 mm) heats up more than the thicker wire (0.6 mm).
This is because a thinner wire offers more resistance to the flow of current, resulting in more heat generation.
For wires of same diameter but different lengths, the longer wire heats up more than the shorter wire because a longer wire offers more resistance.
The heating effect of electric current depends on the material, thickness, and length of the wire, as stated in the chapter.
Explanation
The chapter explains that the heat generated in a wire depends on the material, thickness, and length of the wire, and the duration for which the current flows. A thinner wire offers higher resistance than a thicker wire of the same material and length. Similarly, a longer wire offers more resistance than a shorter wire of the same thickness. Higher resistance leads to more conversion of electrical energy into heat energy.
Solution Steps
Thinner wire (0.3 mm) heats up more than thicker wire (0.6 mm) when length is equal
Thinner wire offers higher resistance to current flow, causing more heat generation
Longer wire heats up more than shorter wire when diameter is the same
Longer wire offers more resistance than shorter wire of same thickness
Heating effect depends on material, thickness, length of wire, and duration of current flow