Semiconductor Devices and Logic Gates

In the band structure of n-type semiconductor , the free electrons donated by impurity atoms occupy energy levels in

In a common emitter transistor amplifier, AC current gain is $65$, the load resistance is $5400\,\Omega$ and input resistance of the transistor is $450\,\Omega$. The voltage gain is

The output Y of the following digital logic circuit will be '1' (one) for the inputs

The depletion region of p-n junction

In Boolean expression $A + B = Y$ implies that

In n-type semiconductorA) pentavalent impurity are dopants and holes are majority carriers.B) trivalent impurity are dopants and electrons are minority carriers.C) pentavalent impurity are dopants and electrons are majority carriers.D) triv...

For a two input logic gate, when the inputs are 'zero' and 'zero' the output is 'one'. When the inputs are 'one' and 'zero' the output is 'zero'. The type of logic gate is

The material used for solar cell should have band gap(A) equal to zero.(B) equal to $0.08$ eV.(C) between $1.0$ eV to $1.8$ eV.(D) equal to $2$ eV.

In the following electrical circuit, the reading in the milliammeter is(Take knee voltage of silicon diode $= 0.7$ V)

In a transistor, comparing the doping of emitter, base and collector, the part which is heavily doped and that which is lightly doped are respectively

The Boolean expression for the given combination of logic gates is

A diode and resistance are connected as shown in figures.Out of the following statements, which one is true?Diode inA) fig (1) and fig (2) are both forward biased.B) fig (1) and fig (2) are both reverse biased.C) fig (1) is forward biased a...

Which of the following logic gates will have an output of '1' (one) for the given inputs?

Which one of the following statements is 'WRONG' regarding LED?

For intrinsic semiconductor, if $n_h$ and $n_e$ represent the number of holes per unit volume and the number of free electrons per unit volume respectively then

The output Y of the given logic circuit is

In an NPN transistor, the collector current is 28 mA. If 80% electrons reach the collector, its base current in mA is

In the circuit shown in figure all the three diodes D1, D2, D3 have forward resistance $50\ \Omega$ each and infinite backward resistance. If the battery voltage is 5V, the current through $100\ \Omega$ resistance is

When the Zener diode is used as a voltage regulator, it is connected in

To get the truth table shown from the following logic circuit, the gate G should be

A semiconductor X is made by doping a germanium crystal with indium $(Z = 49)$. A second semiconductor Y is made by doping germanium crystal with arsenic $(Z = 33)$. Both are joined end to end and connected to a battery as shown. Which of t...

In common emitter configuration of transistor amplifier, $r_i$, $R_L$ and $\beta$ represent the input resistance, load resistance and the a.c. current gain respectively. The voltage gain $A_V$ and power gain $A_P$ are represented in magnitu...

In the following digital circuit, the output 'Y' will be '1' (one) for inputs 'A' and 'B' having values

When a small amount of impurity atoms are added to a semiconductor then generally its resistivity

The resultant gate and its Boolean expression in the given circuit is

In a transistor amplifier, a change of 0.2 mA in the base current causes a change of 5 mA in the collector current. If input resistance is $2\ \text{k}\Omega$ and voltage gain is 75, the load resistance used in the circuit is

In which of the logic gate the following statement is true? "The output is high when either of the inputs is high but not if both inputs are high"

Which of the following statement is NOT correct in the case of LED?(A) It is a heavily doped p-n junction diode.(B) It emits light only when it is forward biased.(C) It emits light only when it is reverse biased.(D) The energy of the light ...

Electrical conductivity of insulators is

If p-n junction diode is forward biased then

For a p-n junction diode, breakdown voltage occurs when

Photodiode is a device

In common emitter amplifier, a change of $0.2$ mA in the base current causes a change of $5$ mA in the collector current. If input resistance is $2$ k$\Omega$ and voltage gain is $75$, the load resistance used in the circuit is

In the diagram shown, the resistance between points A and B is '$R_1$' when an ideal diode D is forward biased and is '$R_2$' when ideal diode D is reverse biased. The ratio $R_1 / R_2$ is

In the logic circuit diagram, when all the four inputs, A, B, C, D are 'one' the outputs $Y_1$, $Y_2$, $Y_3$ are respectively (1, 1, 0). When the inputs A and C are changed to zero and B and D are still 'one', then the outputs $Y_1$, $Y_2$,...

In transistor amplifier, base emitter junction is forward biased and collector base junction is reversed biased. The current gain is

In common emitter mode of transistor, the d.c. current gain is 20, the emitter current is 7 mA. The collector current is

Choose the correct statement about Zener diode:

If transistor having $\alpha = 0.9$, is used in CE configuration, then for a change of $0.4$ mA in base current, what will be the change in collector current?

A pure silicon crystal at temperature $300$ K has electron and hole concentration ($n_i$) $10^{16}$ per m$^3$ each and $10^{21}$ phosphorus atoms ($n_e$) are added per cubic metre. The new hole concentration in silicon crystal is

When the conductivity of a semiconductor is only due to breaking of covalent bonds, the semiconductor is called

In common emitter transistor amplifier, the output resistance is $500$ k$\Omega$ and the current gain $\beta = 50$. If power gain of amplifier is $5 \times 10^6$, what is the input resistance?

What does the following combination of gates produce?

In energy band diagram of insulators, a band gap and the conduction band is respectively

In the case of NAND gate, if A and B are inputs and Y is the output then

In common emitter mode of transistor, the d.c. current gain is $20$, the emitter current is $7$ mA. The collector current is

Which of the following figure represents forward bias diode?

An AND gate is followed by a NOT gate in series. With two inputs ' $A$ ' and ' $B$ ', the Boolean expression for the output ' Y ' will be

When LED is manufactured by using aluminium gallium arsenide (AlGaAs), it emits

The material used for solar cell should have band gap