Which of the following is correct? 

This question was previously asked in
KVS TGT WET (Work Experience Teacher) Official Paper
View all KVS TGT Papers >
  1. Conductors and extrinsic semiconductors have negative temperature coefficient and intrinsic semiconductors have positive temperature coefficient.
  2. Insulators and semiconductors have positive temperature coefficient whereas conductors have negative temperature coefficient.
  3. Conductors and extrinsic semiconductors have positive temperature coefficient and pure semiconductors have negative temperature coefficient.
  4. Intrinsic and extrinsic semiconductors have negative temperature coefficient and conductors have positive temperature coefficient.

Answer (Detailed Solution Below)

Option 4 : Intrinsic and extrinsic semiconductors have negative temperature coefficient and conductors have positive temperature coefficient.
Free
KVS TGT Mathematics Mini Mock Test
70 Qs. 70 Marks 70 Mins

Detailed Solution

Download Solution PDF

Concept:

Temperature coefficient of resistance (α) :

  • The change in electrical resistance of a substance with respect to a per degree change in temperature.
  • α depends on the type of material.

Variation of resistance with temperature:

Let R and RT represent the resistance at a temperature of T0 and T respectively. Therefore

RT = R[1+ α (T-T0)]

Where α is the temperature coefficient of resistance.

Explanation:

α for conductors:  

  • In metal, if the temperature increases, the resistance of the metal increases with the rise in temperature.
  • So, we consider the temperature coefficient of resistance as positive for metal.

α for semiconductor:

  • If temperature increases, the number of electrons come to the conduction bands from valence bands by crossing the forbidden energy gap.
  • As the number of free electrons increases, the resistance of this type of non-metallic substance decreases with an increase in temperature.

Hence, the temperature coefficient of resistance is negative for non-metallic substances and semiconductors.

Both Intrinsic & Extrinsic Semiconductors will have negative temperature coefficient. Conductors have positive temperature coefficient. 

Latest KVS TGT Updates

Last updated on May 8, 2025

-> The KVS TGT Notiifcation 2025 will be released for 16661 vacancies.

-> The application dates will be announced along with the official notification.

-> Graduates with B.Ed or an equivalent qualification are eligible for this post.

-> Prepare with the KVS TGT Previous Year Papers here.

Hot Links: teen patti customer care number all teen patti master teen patti sweet online teen patti teen patti diya