14.9 In an intrinsic semiconductor the energy gap Eg is 1.2eV. Its hole mobility is much smaller than electron mobility and independent of temperature. What is the ratio between conductivity at 600K and that at 300K? Assume that the temperature dependence of intrinsic carrier concentration ${\mathit{n}}_{\mathit{i}}$ is given by

${\mathit{n}}_{\mathit{i}}={\mathit{n}}_0\mathit{}\mathit{e}\mathit{x}\mathit{p}\left(-\frac{{\mathit{E}}_{\mathit{g}}}{2{\mathit{k}}_{\mathit{B}}\mathit{T}}\right)$ where  ${\mathit{n}}_0$ is a constant.

The current flow through the resistance in the given circuit is : (Cut-off voltage for both diodes is 0.7 V)

A n-p-n transistor can be used as

The output (X) of the logic circuit shown in figure will be

 

In the above diagram, balance length for E' is ℓ₀. If cross sectional area of wire AB is doubled then what will be new balancing length ?

The figure shows a logic circuit with two inputs A and B and an output C. The voltage wave forms of A, B and C are as given, then logic circuit will be equivalent to :-