The effect of increase in temperature on the number of electrons in conduction band ($\mathrm{n}_{\mathrm{e}}$) and resistance of a semiconductor will be as:

(C) $n_{e}$ increases, resistance decreases

(A) Both $n_{e}$ and resistance decrease

(B) Both $\mathrm{n}_{\mathrm{e}}$ and resistance increase

(D) $n_{e}$ decreases, resistance increases

JEE Main · 2023 · 31 Jan 2023 · Shift 1 · Semiconductors

The effect of increase in temperature on the number of electrons in conduction band (

n_{e}

) and resistance of a semiconductor will be as:

(A)Both $n_{e}$ and resistance decrease
(B)Both $n_{e}$ and resistance increase
(C) $n_{e}$ increases, resistance decreases✓ Correct
(D) $n_{e}$ decreases, resistance increases

Answer: (C)

Solution

Raising the temperature of a semiconductor gives more valence electrons enough thermal energy to cross the gap into the conduction band, so the number of conduction electrons

n_{e}

grows. With more carriers available to carry current the conductivity rises, and since resistance varies inversely with conductivity, the resistance falls. Heating the semiconductor therefore increases

n_{e}

while its resistance decreases.

JEE Main · 2023 · 31 Jan 2023 · Shift 1 · Single correct option

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JEE Main · 2023 · 31 Jan 2023 · Shift 1 · Semiconductors

Solution

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