Techno Test-2
Electronic Devices
Q.1) In a photodiode, the open circuit photovoltaic potential varies as
| a) square of the light intensity |
b) linearly with light intensity
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c) logarithmically with light intensity
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d) none of the above. |
Q.2) Which of the following material cannot be used to fabricate a light emitting diode
| a) GaAs |
b) AlGaAs
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| c) GaAsP |
d) Si
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Q.3) A tunnel diode
(1) is used in an oscillator.
(2) has greater breakdown voltage than ordinary diode
(3) is like a linear resister in reverse bias
(4) has heavily doped p-n junctions
| a) 1 & 4 |
b) 2 & 4 |
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| c) 1, 3 & 4 |
d) 1 & 3 |
Q.4) A non ideal diode is connected to a battery in series with a resistance such that the diode is forward biased and conducting with voltage drop of 0.7 Volts. Suddenly the polarity of the battery is reversed at t=0. Just after that (i.e. at t=0+)
| a) Current will flow in opposite direction |
b) No current will flow |
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| c) the voltage across the diode is -ve |
d) the voltage across the diode is zero |
Q.5) For proper functioning of a BJT (npn) device, the width of the base region must be kept
| a) much greater than diffusion length Ln of the electron |
b) much lesser than diffusion length Ln of the electron |
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| c) twice the diffusion length Ln of the electron |
d) none of the above |
Deja Vu
| Q1)The early effect in a BJT is caused by |
(GATE 1999) |
| a)fast turn-on |
b)fast turn off |
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| c)large collector-base reverse bias |
d) large emitter-base forward bias |
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| Q2)MOSFET can be used as a |
(GATE 2001) |
a)current controlled capacitor
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b)voltage controlled capacitor
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c)current controlled inductor
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d)voltage controlled inductor
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| Q3)The effective channel length modulation of a MOSFET in saturation decrese with increase in |
(GATE 2001) |
| a)gate voltage |
b)drain voltage |
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| c)source voltage |
d) body voltage |
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| Q4)n-type silicon is obtained by doping silicon with |
(GATE 2003) |
| a)Germanium |
b)Aluminium |
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| c)Boron |
d)Phosphorus |
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| Q5)The bandgap of si at 300K is |
(GATE2003) |
| a)1.36ev |
b)1.10ev |
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| c)0.80ev |
d)0.67ev |
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Q6)Choose proper substitutes for X and Y to make the following statement correct Tunnel diode and Avalanche photodiode are operated in X bias Y bias respectively
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(GATE 2003) |
| a)reverse,reverse |
c)forward,reverse |
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| c)forward,reverse |
d)forward,forward |
- "Click here" to submit your answers, for Techno Test only.
- Answers should reach us latest by 5 PM on April 4, 2010.
- Only first entry will be considered as a valid entry.
- Answers through email will not be entertained.
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