GATE EC Electronic Devices questions

In the figure, the $\text{LED}$

The units of $\frac{q}{k T}$ are

A long specimen of $p$-type semiconductor material

The electron and hole concentrations in a intrinsic semiconductor are $n_i$ and $p_i$ respectively. When doped with a $p$-type material, these change to $n$ and $p$, respectively. Then

For a $\text{MOS}$ capacitor fabricated on a $p$-type semiconductor, strong inversion occurs when

The intrinsic carrier density at $300 \mathrm{~K}$ is $1.5 \times 10^{10}$ / $\mathrm{cm}^{3}$, in silicon. For $n$-type silicon doped to $2.25 \times$ $10^{15}$ atoms $/ \mathrm{cm}^{3}$, the equilibrium electron and hole densities are

The $p$ – type substrate in a conventional $p n$ – junction isolated integrated circuit should be connected to

Copper behaves as a

The depletion capacitance, $\mathrm{C}_{\mathrm{J}}$, of an abrupt $\mathrm{P}-\mathrm{N}$ junction with constant doping on either side varies with reverse bias, $V_{R^{\prime}}$ as

In a $\text{P}$ type silicon sample, the hole concentration is $2.25 \times 10^{15} / \mathrm{cm}^{3}$. If the intrinsic carrier concentration is $1.5 \times 10^{10} / \mathrm{cm}^{3}$, the electron concentration is

The diffusion potential across a $\text{P-N}$ junction

The drift velocity of electrons, in silicon

The probability that an electron in a metal occupies the Fermi-level at any temperature $(>0 \mathrm{~K})$

A small concentration of minority carries is injected into a homogeneous semiconductor crystal at one point. An electric field of $10 \mathrm{~V} . \mathrm{cm}$ is applied across the crystal and this moves the minority carriers a distance of $1 \mathrm{~cm}$ is $20 \; \mu \; \mathrm{sec}$. The mobility (in $\mathrm{cm}^{2} /$ volt. sec) will be

The built-in potential (Diffusion Potential) in a $p-n$ junction

An infrared $\text{LED}$ is usually fabricated from

A semiconductor is irradiated with light such that carriers are uniformly generated throughout its volume. The semiconductor is $n$-type with $N_{D}=10^{19}$ per $\mathrm{cm}^{3}$. If the excess electron concentration in the steady state is $\Delta n=10^{15}$ per $\mathrm{cm}^{3}$ and if $\tau_{p}=10 \mu \sec$ [minority carrier life time] the …