Question
Physics Question on Electromagnetic induction
Which of the following has negative temperature coefficient of resistance?
A
Copper
B
Aluminium
C
Iron
D
Germanium
Answer
Germanium
Explanation
Solution
Key Idea: Temperature coefficient of resistance of semiconductor is negative. Solids whose electrical conductivity is intermediate between conductors and insulators are called semiconductors. Germanium is one such example. The temperature coefficient of resistance of semiconductors is negative, that is, their electrical resistance decreases (or conductivity increases) with rise in temperature. Note: At absolute zero a semiconductor becomes an ideal insulator.