Question

The variations of resistivity \( \rho \) with absolute temperature \( T \) for three different materials X, Y, and Z are shown in the graph below. Identify the materials X, Y, and Z. 

• A. X = nichrome, Y = copper, Z = semiconductor
• B. X = copper, Y = nichrome, Z = semiconductor
• C. X = copper, Y = semiconductor, Z = nichrome
• D. X = semiconductor, Y = nichrome, Z = copper

Hint:

In a typical metal, resistivity increases with temperature, while in a semiconductor, resistivity decreases as temperature increases. This is due to the increasing number of charge carriers in semiconductors at higher temperatures.

Answer 1

The Correct Option is A

The graph shows the relationship between resistivity \( \rho \) and temperature \( T \). For most materials, resistivity increases with temperature, but the rate of change varies depending on the material. - Material X shows a steep increase in resistivity with temperature, which is characteristic of nichrome (a metal with a high positive temperature coefficient of resistance). - Material Y shows a relatively moderate increase in resistivity, which is characteristic of copper (a metal with a lower positive temperature coefficient of resistance). - Material Z shows a small decrease in resistivity with temperature, which is characteristic of a semiconductor (which has a negative temperature coefficient of resistance). Thus, the materials are identified as: - X = nichrome, Y = copper, Z = semiconductor.