Semi conductor devices practice · Medium

The energy band gap (distance between the conduction band and valence band) in conductor is

What is the coordination number of sodium ions in the case of sodium chloride structure

The input resistance of a CE amplifier is $5 \mathrm{k \Omega}$ and the load resistance is $20 \mathrm{k} \Omega$. If the current gain is 100 then mutual conductance of the transistor used is

Diode is not considered as linear device because

Following is the relation between current and charge $I = A{T^2}{e^{q/{V_L}}}$, then value of ${V_L}$ will be

The reason of current flow in $P$-$N$ junction in forward bias is

In a transistor if collector current is 25 mA and base current is 1 mA, then current amplification factor $\propto$ is

The $PN$ junction diode is used as

In an experiment, the saturation in the plate current in a diode is observed at $240V$. But a student still wants to increase the plate current. It can be done, if

In $P$-$N$ junction, avalanche current flows in circuit when biasing is

Forward bias characteristics of a p-n junction diode is used in which of the following devices?

Biaxial crystal among the following is

When phosphorus and antimony are mixed in germanium, then

A npn transistor is connected in common emitter configuration in a given amplifier. A load resistance of $800\,\Omega$ is connected in the collector circuit and the voltage drop across it is 0.8 V. If the current amplification factor is 0.96 and the input resistance of the circuit is $192\,\Omega$ , the voltage gain and the power gain of the amplifier will respectively be:

When a solid with a band gap has a donor level just below its empty energy band, the solid is

Carbon, silicon and germanium have four valence electrons each. At room temperature which one of the following statements is more appropriate?

Assertion : In an unbiased p-n junction, holes diffuse from the p-region to n-region.

Reason : Whole concentration in p-region is more as compared to n-region.

Energy bands in solids are a consequence of

Assertion : If the temperature of a semiconductor is increased, its resistance decreases.

Reason : The energy gap between conduction band and valence band in case of semiconductor is small.

The charge carries in a $p$-type semiconductor are

With the rise in temperature, the electrical conductivity of intrinsic semiconductor

A $P$-type semiconductor has acceptor levels $57\;meV$ above the valence band. The maximum wavelength of light required to create a hole is (Planck’s constant $h = 6.6 \times {10^{ - 34}}J$-s)

For which of the following the resistance decreases on increasing the temperature

If ${n_e}$ and ${n_h}$ are the number of electrons and holes in a semiconductor heavily doped with phosphorus, then

Pure Si at temperature of $300 \mathrm{~K}$ has same electron $\left(\mathrm{n}_{\mathrm{e}}\right)$ and hole $\left(\mathrm{n}_{\mathrm{k}}\right)$ concentrations of $1.5 \times 10^{16} \mathrm{~m}^{-3}$. Doping by 'In' increases $\mathrm{n}_{\mathrm{h}}$ to $3 \times 10^{22}$ $\mathrm{m}^{-3}$. Calculate $\mathrm{n}_{\mathrm{e}}$ in the doped $\mathrm{Si}$.

Minority carriers in a $p$-type semiconductor are

The decimal equivalent of the binary number ${\left( {11010.101} \right)_2}$ is

Using Boolean algebra, the value of $(A \cdot B)+A$ is equal to

Assertion : Absorption factor for $\mathrm{GaAs}$ is larger as compared to $\mathrm{Si}$ for sunlight.

Reason : $\Delta \mathrm{E}_{\mathrm{g}}$ is more for $\mathrm{GaAs}$.

For an insulator the forbidden energy gap is