Question

Assertion (A) : The temperature coefficient of resistance is positive for metals and negative for p-type semiconductors. Reason (R) : The charge carriers in metals are negatively charged, whereas the majority charge carriers in p-type semiconductors are positively charged.

When an intrinsic semiconductor is doped with a small amount of trivalent impurity, then :

Differentiate between intrinsic and extrinsic semiconductors.

At a certain temperature in an intrinsic semiconductor, the electrons and holes concentration is 1·5 × 10¹⁶ m⁻³. When it is doped with a trivalent dopant, hole concentration increases to 4·5 × 10²² m⁻³. In the doped semiconductor, the concentration of electrons (nₑ) will be :