Question:
Which of the following has negative temperature coefficient of resistance?
Which of the following has negative temperature coefficient of resistance?
Updated On: Jul 7, 2022
- Copper
- Aluminium
- Iron
- Germanium
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The Correct Option is D
Solution and Explanation
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.
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Concepts Used:
Electromagnetic Induction
Electromagnetic Induction is a current produced by the voltage production due to a changing magnetic field. This happens in one of the two conditions:-
- When we place the conductor in a changing magnetic field.
- When the conductor constantly moves in a stationary field.
Formula:
The electromagnetic induction is mathematically represented as:-
e=N × d∅.dt
Where
- e = induced voltage
- N = number of turns in the coil
- Φ = Magnetic flux (This is the amount of magnetic field present on the surface)
- t = time
Applications of Electromagnetic Induction
- Electromagnetic induction in AC generator
- Electrical Transformers
- Magnetic Flow Meter