The circuit diagram shown here corresponds to the logic gate:

     
1. \(\text{NOR}\)
2. \(\text{AND}\)
3. \(\text{OR}\)
4. \(\text{NAND}\)

Subtopic:  Logic gates |
 52%
Level 3: 35%-60%
NEET - 2019
Hints

An LED is constructed from a \(\mathrm{p\text{-}n}\) junction diode using \(\mathrm{GaAsP}.\) The energy gap is \(1.9~\text{eV}.\) The wavelength of the light emitted will be equal to:
1. \(10.4 \times 10^{-26}~ \text{m}\)
2. \(654~ \text{nm}\)
3. \(654~ \text{m}\)
4. \(654\times 10^{-11}~\text{m}\)

Subtopic:  Applications of PN junction |
 80%
Level 1: 80%+
NEET - 2019
Hints

The figure shows a logic circuit with two inputs \(A\) and \(B\) and the output \(C\). The voltage waveforms across \(A\), \(B\), and \(C\) are as given. The logic circuit gate is:
         

1. \(\text{OR}\) gate
2. \(\text{NOR}\) gate
3. \(\text{AND}\) gate
4. \(\text{NAND}\) gate

Subtopic:  Logic gates |
 85%
Level 1: 80%+
AIPMT - 2012
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\(\mathrm{C}\) and \(\mathrm{Si}\) both have the same lattice structure, having \(4\) bonding electrons in each. However, \(\mathrm{C}\) is an insulator whereas \(\mathrm{Si}\) is an intrinsic semiconductor. This is because:
1. in the case of \(\mathrm{C},\) the valence band is not completely filled at absolute zero temperature.
2. in the case of \(\mathrm{C},\) the conduction band is partly filled even at absolute zero temperature.
3. the four bonding electrons in the case of \(\mathrm{C}\) lie in the second orbit, whereas in the case of \(\mathrm{Si},\) they lie in the third.
4. the four bonding electrons in the case of \(\mathrm{C}\) lie in the third orbit, whereas for \(\mathrm{Si},\) they lie in the fourth orbit.
Subtopic:  Energy Band theory |
 72%
Level 2: 60%+
NEET - 2012
Hints

Two ideal diodes are connected to a battery as shown in the circuit. The current supplied by the battery is:

1. \(0.75~\text{A}\) 2. zero
3. \(0.25~\text{A}\) 4. \(0.5~\text{A}\)
Subtopic:  PN junction |
 88%
Level 1: 80%+
AIPMT - 2012
Hints

The barrier potential of a \(\mathrm{p\text{-}n}\) junction depends on:
(a) type of semiconductor material 
(b) amount of doping 
(c) temperature 

Which one of the following is correct?

1. (a) and (b) only 2. (b) only
3. (b) and (c) only 4. (a), (b) and (c)
Subtopic:  PN junction |
 84%
Level 1: 80%+
NEET - 2014
Hints

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Which logic gate is represented by the following combination of logic gates? 

    
1. \(\mathrm{OR}\)
2. \(\mathrm{NAND}\)
3. \(\mathrm{AND}\)
4. \(\mathrm{NOR}\)
Subtopic:  Logic gates |
 72%
Level 2: 60%+
NEET - 2015
Hints

If in a \(\mathrm{p\text{-}n}\) junction, a square input signal of \(10~\text{V}\) is applied as shown, 

 
then the output across \(R_L\) will be:

1. 2.
3. 4.
Subtopic:  PN junction |
 71%
Level 2: 60%+
NEET - 2015
Hints

In the given figure, a diode \(D\) is connected to an external resistance \(R = 100~\Omega\) and an EMF of \(3.5~\text{V}\). If the barrier potential developed across the diode is \(0.5~\text{V}\), the current in the circuit will be:
  
1. \(30~\text{mA}\)
2. \(40~\text{mA}\)
3. \(20~\text{mA}\)
4. \(35~\text{mA}\)

Subtopic:  PN junction |
 75%
Level 2: 60%+
NEET - 2015
Hints

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The given circuit has two ideal diodes connected as shown in the figure below. The current flowing through the resistance \(R_1\) will be:

1. \(2.5~\text{A}\) 2. \(10.0~\text{A}\)
3. \(1.43~\text{A}\) 4. \(3.13~\text{A}\)
Subtopic:  PN junction | Applications of PN junction |
 88%
Level 1: 80%+
NEET - 2016
Hints