Semiconductors & Communication · JEE Main previous year questions

2018 5 questions

1. Q562018 · 16 Apr 2018 · Shift 1
   
   1. A.5.5 mA
   2. B.6.7 mA
   3. C.2.5 mA
   4. D.3.3 mA
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   Answer: D

2. Q602018 · 16 Apr 2018 · Shift 1

   A carrier wave of peak voltage 14 V is used for transmitting a message signal. The peak voltage of modulating signal given to achieve a modulation index of 80% will be :

   1. A.7 V
   2. B.28 V
   3. C.11.2 V
   4. D.22.4 V
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   Answer: C

3. Q422018 · 15 Apr 2018 · Shift 1

   Light of wavelength $550nm$ falls normally on a slit of width $22.0\times 10^{-5}cm$. The angular position of the second minima from the central maximum will be (in radians) :

   1. A.$\frac{\pi }{12}$
   2. B.$\frac{\pi }{8}$
   3. C.$\frac{\pi }{6}$
   4. D.$\frac{\pi }{4}$
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   Answer: C

4. Q572018 · 8 Apr 2018 · Shift 1
   
   1. A.13.5 mA
   2. B.0
   3. C.15 mA
   4. D.11.5 mA
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   Answer: D

5. Q592018 · 8 Apr 2018 · Shift 1

   A telephonic communication service is working at carrier frequency of 10 GHz. Only 10% of it is utilized for transmission. How many telephonic channels can be transmitted simultaneously if each channel requires a bandwidth of 5 kHz ?

   1. A.$2\times 10^6$
   2. B.$2\times 10^3$
   3. C.$2\times 10^5$
   4. D.$2\times 10^4$
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   Answer: C