Semiconductors & Communication · JEE Main previous year questions

2024 11 questions

1. Q362024 · 9 Apr 2024 · Shift 1

   A light emitting diode (LED) is fabricated using GaAs semiconducting material whose band gap is $1.42\text{ eV}$. The wavelength of light emitted from the LED is :

   1. A.1243 nm
   2. B.875 nm
   3. C.650 nm
   4. D.1400 nm
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   Answer: B

2. Q542024 · 8 Apr 2024 · Shift 2· Numerical answer
   
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   Answer: 5

3. Q362024 · 6 Apr 2024 · Shift 2

   The acceptor level of a p-type semiconductor is $6\mathrm{eV}$. The maximum wavelength of light which can create a hole would be : Given $\mathrm{hc}=1242\mathrm{eV}\mathrm{nm}$.

   1. A.$407\mathrm{nm}$
   2. B.$103.5\mathrm{nm}$
   3. C.$414\mathrm{nm}$
   4. D.$207\mathrm{nm}$
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   Answer: D

4. Q502024 · 4 Apr 2024 · Shift 2
   
   1. A.OR gate
   2. B.NAND gate
   3. C.NOR gate
   4. D.AND gate
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   Answer: A

5. Q532024 · 4 Apr 2024 · Shift 2· Numerical answer

   A bus moving along a straight highway with speed of $72\text{ km/h}$ is brought to a halt within $4s$ after applying the brakes. The distance travelled by the bus during this time (Assume the retardation is uniform) is ________ $m$.

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   Answer: 40

6. Q472024 · 1 Feb 2024 · Shift 2

   Conductivity of a photodiode starts changing only if the wavelength of incident light is less than $660\text{ nm}$. The band gap of photodiode is found to be $\left(\frac{\mathrm{X}}{8}\right)\text{eV}$. The value of $\mathrm{X}$ is : (Given, $\mathrm{h}=6.6\times 10^{-34}\text{Js},\mathrm{e}=1.6\times 10^{-19}\text{C}$ )

   1. A.11
   2. B.13
   3. C.15
   4. D.21
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   Answer: C

7. Q442024 · 30 Jan 2024 · Shift 1
   
   1. A.0
   2. B.$30\text{ mA}$
   3. C.$20\text{ mA}$
   4. D.$50\text{ mA}$
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   Answer: B

8. Q462024 · 29 Jan 2024 · Shift 1
   
   1. A.$3.3\text{ mA}$
   2. B.$10\text{ mA}$
   3. C.$5.5\text{ mA}$
   4. D.$7\text{ mA}$
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   Answer: C

9. Q582024 · 29 Jan 2024 · Shift 2· Numerical answer

   A particle is moving in a circle of radius $50\text{ cm}$ in such a way that at any instant the normal and tangential components of it's acceleration are equal. If its speed at $t=0$ is $4\text{ m/s}$, the time taken to complete the first revolution will be $\frac{1}{\alpha }\left[1-e^{-2\pi }\right]\text{s}$, where $\alpha =$ _________.

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   Answer: 8

10. Q362024 · 27 Jan 2024 · Shift 2

    Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : The angular speed of the moon in its orbit about the earth is more than the angular speed of the earth in its orbit about the sun. Reason (R) : The moon takes less time to move around the earth than the time taken by the earth to move around the sun. In the light of the above statements, choose the most appropriate answer from the options given below :

    1. A.Both (A) and (R) are correct but (R) is not the correct explanation of (A)
    2. B.(A) is correct but (R) is not correct
    3. C.Both (A) and (R) are correct and (R) is the correct explanation of (A)
    4. D.(A) is not correct but (R) is correct
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    Answer: C

11. Q372024 · 27 Jan 2024 · Shift 2

    Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : The property of body, by virtue of which it tends to regain its original shape when the external force is removed, is Elasticity. Reason (R) : The restoring force depends upon the bonded inter atomic and inter molecular force of solid. In the light of the above statements, choose the correct answer from the options given below :

    1. A.(A) is false but (R) is true
    2. B.Both (A) and (R) are true but (R) is not the correct explanation of (A)
    3. C.Both (A) and (R) are true and (R) is the correct explanation of (A)
    4. D.(A) is true but (R) is false
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    Answer: C