Semi conductor devices practice · Medium

In semiconductor diode, the barrier potential offers opposition to flow of

Assertion : When the temperature of a semiconductor is increased, then its resistance decreases

Reason : The energy gap between conduction band and valence band is very small

Assertion: A P-N photodiode is made from a semiconductor for which $\mathrm{Eg}=2.8 \mathrm{eV}$. This photodiode will not detect the wavelength of $6000 \mathrm{~nm}$.

Reason: A PN photodiode detects wavelength I if $\frac{h c}{\lambda} > E_g$

In a cubic unit cell of bcc structure, the lattice points ($ie$, number of atoms) are

In an unbiased p-n junction, holes diffuse from the p-region to n-region because of

Consider the following statements (A) and (B) and identify the correct answer.
(A) Zener diode can be used as voltage regulator.
(B) In unbiased p-n junction, at thermal equilibrium, drift current is equal to diffusion current.

The energy band gap is maximum in

Assertion : Generally semiconductors do not obey Ohm’ law.

Reason : Electric current is determined by the rate of flow of charge carriers.

Why do we prefer indirectly heated cathode to the directly heated cathode?

In $P$-type semiconductor the majority and minority charge carriers are respectively

Radiowaves of constant amplitude can be generated with

A common emitter amplifier has a voltage gain of 50, an input impedance of 100 $\Omega$ and an output impedance of 200$\Omega$ . The power gain of the amplifier is

Calculate the current amplification factor $\beta$ (beta) when change in collector current is 1 mA and change in base current is $20\,\mu A.$

The coordination number of hexagonal close packing (hcp) is

The majority charge carriers in $P$-type semiconductor are

The typical ionisation energy of a donar in silicon is

The energy gap of silicon is 1.14 eV. The maximum wavelength at which silicon starts energy absorption, will be($h = 6.62 \times {10^{ - 34}}\mathrm{\;Js};\mathrm{c} = 3 \times {10^8}\mathrm{m}{\mathrm{s}^{ - 1}}$)

The output from a NAND gate is 0 when the inputs A, B and C are such that.

Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R.

Assertion A: Photodiodes are preferably operated in reverse bias condition for light intensity measurement.

Reason R: The current in the forward bias is more than the current in the reverse bias for a $p-n$ junction diode.

In the light of the above statements, choose the correct answer from the options given below:

In a fcc lattice structure, what is the effective number of atoms?

During regulation action of a Zener diode correct statement is :-

(a) the current and voltage across the Zener remains fixed.

(b) the current through the series resistance $\left(\mathrm{R}_{\mathrm{S}}\right)$ changes.

(c) the Zener resistance is constant.

(d) the resistance offered by the Zener diode changes.

The voltage gain of an amplifier with 9% negative feedback is 10. The voltage gain without feedback will be

The forbidden energy band gap in conductors, semiconductors and insulators are $E{G_1},\;E{G_2}$ and $E{G_3}$ respectively. The relation them is

A transistor oscillator is

(i) An amplifier with positive feedback

(ii) An amplifier with reduced gain

(iii) The one in which DC supply energy is converted into AC output energy. Then

In $CE$ mode, the input characteristics of a transistor is the variation of

In a diode, when there is a saturation current, the plate resistance will be

In a common base amplifier, the phase difference between the input signal voltage and output voltage is

Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: n-p-n transistor permits more current than a p-n-p transistor.
Reason R: Electrons have greater mobility as a charge carrier.
Choose the correct answer from the options given below:

Which of the following gates are called universal gates?

Zenor diode works on the principle of