p-n photodiode is fabricated from a semiconductor with a band gap of 2.5 eV. It can detect a signal of wavelength:
1. 6000 Å
2. 4000 nm
3. 6000 nm
4. 4000 Å
 

Subtopic:  Energy Band theory |
 63%
From NCERT
AIPMT - 2009

To unlock all the explanations of this course, you need to be enrolled.

Hints

To unlock all the explanations of this course, you need to be enrolled.


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

Subtopic:  Logic gates |
 83%
From NCERT
AIPMT - 2012

To unlock all the explanations of this course, you need to be enrolled.

Hints

To unlock all the explanations of this course, you need to be enrolled.


\({C}\) and \({Si}\) both have the same lattice structure, having \(4\) bonding electrons in each. However, \(C\) is an insulator whereas \(Si\) is an intrinsic semiconductor. This is because:

1. in the case of \(C\), the valence band is not completely filled at absolute zero temperature.
2. in the case of \(C\), the conduction band is partly filled even at absolute zero temperature.
3. the four bonding electrons in the case of \(C\) lie in the second orbit, whereas in the case of \(Si\), they lie in the third.
4. the four bonding electrons in the case of \(C\) lie in the third orbit, whereas for \(Si\), they lie in the fourth orbit.
Subtopic:  Energy Band theory |
 71%
From NCERT
NEET - 2012

To unlock all the explanations of this course, you need to be enrolled.

Hints

To unlock all the explanations of this course, you need to be enrolled.


advertisementadvertisement

Zener breakdown will occur if:
1. impurity level is low.
2. impurity level is high.
3. impurity is less on the n-side.
4. impurity is less on the p-side.

Subtopic:  Applications of PN junction |
 75%
From NCERT

To unlock all the explanations of this course, you need to be enrolled.

Hints

To unlock all the explanations of this course, you need to be enrolled.


In the circuit shown in the figure, the maximum output voltage Vo is:

     

1. 0 V

2. 5 V

3. 10 V

4. 52 V

Subtopic:  Rectifier |
Please attempt this question first.
Hints

If the reverse bias in a junction diode is changed from \(5\) V to \(15\) V then the value of current changes from \(38\) \(\mu \text{A}\) to \(88\) \(\mu \text{A}.\) The resistance of junction diode will be:
1. \(4\times10^{5}\) 
2. \(3\times10^{5}\)
3. \(2\times10^{5}\)
4. \(10^{6}\)

Subtopic:  PN junction |
 84%
From NCERT

To unlock all the explanations of this course, you need to be enrolled.

Hints

To unlock all the explanations of this course, you need to be enrolled.


advertisementadvertisement

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 |
 78%
From NCERT
NEET - 2019

To unlock all the explanations of this course, you need to be enrolled.

Hints

To unlock all the explanations of this course, you need to be enrolled.


A potential barrier of 0.50 V exists across a p-n junction. If the depletion region is 5.0×10-7 m wide, the intensity of the electric field in this region is:

1. \(1.0 \times 10^6 \mathrm{~V} / \mathrm{m}\) 2. \(1.0 \times 10^5 \mathrm{~V} / \mathrm{m}\)
3. \(2.0 \times 10^5 \mathrm{~V} / \mathrm{m}\) 4. \(2.0 \times 10^6 \mathrm{~V} / \mathrm{m}\)
Subtopic:  PN junction |
 82%
From NCERT

To unlock all the explanations of this course, you need to be enrolled.

Hints

To unlock all the explanations of this course, you need to be enrolled.


The correct symbol for zener diode is:

1. 2.
3. 4.
Subtopic:  Applications of PN junction |
 90%
From NCERT

To unlock all the explanations of this course, you need to be enrolled.

Hints

To unlock all the explanations of this course, you need to be enrolled.


advertisementadvertisement

The electrical circuit used to get smooth output from a rectifier circuit is called:

1. oscillator.

2. filter.

3. amplifier.

4. logic gates.

Subtopic:  Rectifier |
 60%
From NCERT

To unlock all the explanations of this course, you need to be enrolled.

Hints

To unlock all the explanations of this course, you need to be enrolled.