6. (JEE Main 2024 (Online) 8th April Evening Shift )

A potential divider circuit is connected with a dc source of $20\mathrm{V}$, a light emitting diode of glow in voltage $1.8\mathrm{V}$ and a zener diode of breakdown voltage of $3.2\mathrm{V}$. The length (PR) of the resistive wire is $20\mathrm{cm}$. The minimum length of PQ to just glow the LED is _________ $\mathrm{cm}$.

7. (JEE Main 2023 (Online) 10th April Morning Shift)

A zener diode of powerrating 1.6 W is to be used as voltage regulator. If the zener diode has a breakdown of 8V and it has to regulate voltage fluctuating between 3 V and 10 V. The value of resistance Rs for safe operation of diode will be

A. 13 $\mathrm{\Omega }$

B. 13.3 $\mathrm{\Omega }$

C. 10 $\mathrm{\Omega }$

D. 12 $\mathrm{\Omega }$

8. (JEE Main 2023 (Online) 1st February Evening Shift)

Choose the correct statement about Zener diode :

A. It works as a voltage regulator in reverse bias and behaves like simple pn junction diode in forward bias.

B. It works as a voltage regulator in both forward and reverse bias.

C. It works as a voltage regulator only in forward bias.

D. It works as a voltage regulator in forward bias and behaves like simple pn junction diode in reverse bias.

9. (JEE Main 2023 (Online) 29th January Morning Shift)

Which one of the following statement is not correct in the case of light emitting diodes?

A. It is a heavily doped p-n junction.

B. It emits light only when it is forward biased.

C. It emits light only when it is reverse biased.

D. The energy of the light emitted is equal to or slightly less than the energy gap of the semiconductor used.

Choose the correct answer from the options given below:

A. A

B. B

C. C and D

D. C

10. (JEE Main 2023 (Online) 25th January Morning Shift)

Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R

Assertion A : Photodiodes are used in forward bias usually for measuring the light intensity.

Reason R : For a p-n junction diode, at applied voltage V the current in the forward bias is more than the current in the reverse bias for $|{\mathrm{V}}_{\mathrm{z}}|>\pm \mathrm{v}\ge |{\mathrm{v}}_0|$ where ${\mathrm{v}}_0$ is the threshold voltage and ${\mathrm{V}}_{\mathrm{z}}$ is the breakdown voltage.

In the light of the above statements, choose the correct answer from the options given below

A. Both A and R are true but R is NOT the correct explanation of A

B. A is true but R is false

C. Both A and R are true and R is the correct explanation of A

D. A is false but R is true