Semiconductor Devices and Logic Gates · Physics · AP EAPCET
MCQ (Single Correct Answer)
1
Pure silicon at 300 K has equal electron and hole concentration of $1.5 \times 10^{16} \mathrm{~m}^{-3}$. If the hole concentration increases to $3 \times 10^{22} \mathrm{~m}^{-3}$, then electron concentration in the silicon is
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2
In $n-p-n$ transistor circuit, the collector current is 10 mA . If $95 \%$ of the electrons emitted reach the collector, then the base current is nearly
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3
The semiconductor used for fabrication of visible LEDS must at least have a band gap of
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4
In a common emitter amplifier, AC current gains 40 and input resistance is $2 \mathrm{k} \Omega$. The load resistance is given as $10 \mathrm{k} \Omega$. Then, the voltage gain is
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5
The voltage gain and current gain of a transistor amplifier in common emitter configuration are respectively 150 and 50 . If the resistance in the base circuit is $850 \Omega$, then the resistance in collector circuit is
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6
If the energy gap of a substance is 5.4 eV , then the substance is
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7
A p-n junction diode is used as
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8
When a signal is applied to the input of a transistor, it was found that output signal is phase-shifted by $180^{\circ}$. The transistor configuration is
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9
If $n_r$ and $n_h$ are concentrations of electron and holes in a semiconductor, then the intrinsic carrier concentration $n_j$ in thermal equilibrium is
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10
In the given digital circuit, if the inputs are $A=1 B_x$ and $C=1$, then the value of $Y_1$ and $Y_2$ are respectino
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11
Consider the statements In a semiconductor
(A) There are no free electrons at 0 K.
(B) There are no free electrons at any temperature.
(C) The number of free electrons increases with temperature.
(D) The number of free electrons is less than that in a conductor.
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12
Output of following logic circuit is
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13
The truth table given below corresponds to logic gate.
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14
A transistor is connected in common emitter configuration. The collector supply is $$8 \mathrm{~V}$$ and the voltage drop across a resistor of $$800 \Omega$$ in the collector circuit is $$0.5 \mathrm{~V}$$. If the current gain factor $$\alpha$$ is 0.96, then the base current is
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