In a forward-biased \(\mathrm{p\text-n}\) junction diode, the potential barrier in the depletion region is of the form of:
1. 2.
3. 4.

Subtopic:  PN junction |
 68%
Level 2: 60%+
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The electrical circuit used to get smooth DC output from a rectifier circuit is called:
1. logic gate
2. amplifier
3. filter
4. oscillator
Subtopic:  Rectifier |
 66%
Level 2: 60%+
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A full wave rectifier circuit along with the input and output voltages is shown in the figure. The contribution to the output voltage from diode-\(2\) is:
1. \(A,C\) 2. \(B,D\)
3. \(B,C\) 4. \(A,D\)
 
Subtopic:  Rectifier |
 81%
Level 1: 80%+
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What is responsible for the formation of the depletion layer across the \(\mathrm{p\text-n}\) junction?

1. Drift of holes.
2. Drift of electrons.
3. Diffusion of holes and electrons.
4. Absence of diffusion of holes and electrons.
Subtopic:  PN junction |
 83%
Level 1: 80%+
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The charge on a \(\mathrm{p}\)-type semiconductor is:
 
1. neutral 
2. negative
3. positive
4. may be positive or negative
Subtopic:  Types of Semiconductors |
 74%
Level 2: 60%+
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The energy band gap of semiconducting material to produce violet (wavelength \(=4000~\mathring{A}\)) LED is (nearly):
1. \(3~\text{eV}\)
2. \(5~\text{eV}\)
3. \(1~\text{eV}\)
4. \(7~\text{eV}\)
Subtopic:  Energy Band theory |
 86%
Level 1: 80%+
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The dynamic resistance of a diode is given by; \(R=\dfrac{26}{i(\text{mA})}~\Omega,\) where \(i\) is the diode current.
Statement I: If the current through the diode increases, then the dynamic resistance decreases.
Statement II: If the temperature of the diode is increased, with the potential difference fixed, the dynamic resistance decreases.
 
1. Statement I is incorrect and Statement II is correct.
2. Both Statement I and Statement II are correct.
3. Both Statement I and Statement II are incorrect.
4. Statement I is correct and Statement II is incorrect.
Subtopic:  PN junction |
 73%
Level 2: 60%+
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Potential barrier across a \(\mathrm{p\text-n}\) junction is \(0.6\) V. Electric field intensity, in the depletion region having a width of \(6\times10^{-6}\) m, will be:
1. \(1\times10^{5}\) N/C
2. \(2\times10^{5}\) N/C
3. \(3\times10^{5}\) N/C
4. \(4\times10^{5}\) N/C
Subtopic:  PN junction |
 92%
Level 1: 80%+
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An intrinsic Germanium \(\mathrm{(Ge)}\) semiconductor having \(2.5 \times 10^{29}\) atoms per \(\text m^3\) is doped uniformly by trivalent aluminium at \(1~\text{ppm}.\)If the thermally generated electron concentration at room temperature is \(n_i=10^{17}/\text m^3,\) the resulting electron concentration after doping at the same temperature will be:
1. \(2.5 \times 10^{29}~\text m^{-3}\)
2. \(4 \times 10^{10}~\text m^{-3}\)
3. \(2.5 \times 10^{18}~\text m^{-3}\)
4. \(4 \times 10^{20}~\text m^{-3}\) 
Subtopic:  Types of Semiconductors |
 73%
Level 2: 60%+
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A \(\mathrm{Ge}\) specimen is doped with \(\mathrm{Al}.\) The concentration of acceptor atoms is approximately \(10^{24}~\text{m}^{-3}.\) Given that intrinsic carrier concentration is nearly \(10^{19}~\text{m}^{-3},\) then the concentration of electrons in the specimen is nearly:
1. \(10^{10}~\text{m}^{-3}\)
2. \(10^{14}~\text{m}^{-3}\)
3. \(10^{19}~\text{m}^{-3}\)
4. \(10^{18}~\text{m}^{-3}\)
Subtopic:  Types of Semiconductors |
 83%
Level 1: 80%+
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