Hey guys and gurus I can't understand question part a) and part b). The diagram is for part b) question. Please help me solve this question guys thank you very much

 

I cant seem to understand the part a) question at all

 

Do you have a textbook to read the diode theory? It's not rocket science, but it's not trivial either. You should learn some basics before attempting exercises. Wikipedia has a I-V graph on the topic "diode", wich is the one you need. The right half-plane will be sufficient in your case.

Is, Vt and n, are quantities characteristic of the diode. Is ranges at \(10^{-15}\) amps. n is 1 or 2, depending on the diode. Vt is usually taken as a constant at about 25mV.

Vd, is the voltage applied on the diode.

Once you understand how diodes work, you can attempt question b. The way to go there, is to assume one, or two diodes are active, then try to measure the resulting voltages. If they confirm your initial assumption, you are good to go. Otherwise, the opposite stands true.

 

You just need to learn some basics about the diode. Once you have understood the I-V characteristic of the diode,you'll find it's easy to solve the two questions.