MHT CET202521 Apr 2025Morning ShiftPhysicsSemiconductorsActual
Which graph shows correctly the temperature (T) dependence of resistivity ( ) of a semiconductor?
Options
- AC
- BA
- CD
- DB
Correct answer
A. C
Step-by-step solution
The resistivity of a semiconductor varies with temperature according to the relation = ₀ e^ E_g / (2k_B T) , where ₀ is a constant, E_g is the band gap energy, k_B is Boltzmann’s constant, and T is the absolute temperature. As T increases, the exponential term e^ E_g / (2k_B T) decreases, leading to a reduction in . This follows from increased thermal excitation of charge carriers across the band gap, enhancing conductivity. Since resistivity is the reciprocal of conductivity, it declines with rising temperature. G