A $8\mathrm{V}$ Zener diode along with a series resistance $R$ is connected across a $20 \mathrm{V}$ supply (as shown in the figure). If the maximum Zener current is $25 \mathrm{mA}$, then the minimum value of $R$ will be _____ $\mathrm{\Omega }$.

For the forward biased diode characteristics shown in the figure, the dynamic resistance at $I_D=3 \mathrm{mA}$ will be ________$\mathrm{\Omega }.$

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

Assertion A: Photodiodes are preferably operated in reverse bias condition for light intensity measurement.
Reason R: The current in the forward bias is more than the current in the reverse bias for a $p-n$ junction diode.

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

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 $\left|V_z\right|>\pm V\ge \left|V_0\right|$ where $V_0$ is the threshold voltage and $V_z$ is the breakdown voltage.

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

Statement I : When a Si sample is doped with Boron, it becomes P type and when doped by Arsenic it becomes N-type semi conductor such that P-type has excess holes and N-type has excess electrons.

Statement II : When such P-type and N-type semi-conductors, are fused to make a junction, a current will automatically flow which can be detected with an externally connected ammeter.

In the light of above statements, choose the most appropriate answer from the options given below.

Which 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 :

Match the List I with List II

Choose the correct answer from the options given below: