Confusing yet simple looking problem - DC analysis of diode & xstr

[Cetullah]

Homework Statement

DC analysis is required for the question in attachment.
Vz=6V
B=100
Vbe=0.7V

Homework Equations

The Attempt at a Solution

I tried to find the result using the currents that were defined by the transistor. I found a result that was nonsense, the base current Ib was negative, which is impossible.
Given in the attachment too.

Note: I have an exam tomorrow people. Would be awesome if you have guided me. Thanks

 

[mfb]

It is impossible to tell what you did wrong if you do not show your work...

 

[rude man]

Don't use an equivalent circuit for dc analysis. Equiv. ckts. are for small variations about the bias point. Your job is to find the bias point.

Hints:
what must be the emitter voltage if the zener is on?
so then what must be the emitter current?
so then what is the collector voltage?
was your assumption that the zener is on, valid? why?

 

[Alpharup]

See where you have placed the 0.7 V voltage drop. Shouldn't it be in 2kilo-ohm resistor branch? Shouldn't there be a short where you have placed the 0.7 volt drop in the above diagram? See this and you can solve.

 

[rezeew]

I understand your frustration with this problem. It can be confusing to approach a problem that seems simple on the surface, but ends up being more complex than expected. In this case, it is important to carefully review the given information and equations to make sure all variables are accounted for and used correctly.

First, let's review the given information. We are analyzing a diode and a transistor, and we are given the values for Vz (the voltage across the diode), B (the transistor's gain), and Vbe (the voltage between the base and emitter of the transistor). These values are important for understanding the behavior of the circuit.

Next, we need to review the equations that are relevant to this problem. The most important equation to consider is Ohm's Law, which states that V = IR, where V is voltage, I is current, and R is resistance. This equation can be used to analyze the flow of current through the diode and transistor in this circuit.

Now, let's look at the attempt at a solution. It seems that you have correctly used the equations for the currents defined by the transistor, but have ended up with a negative base current (Ib). This is not physically possible, as current cannot flow in the opposite direction of the defined current flow. This could indicate an error in the calculation or a misunderstanding of the circuit.

To guide you towards a solution, I would suggest reviewing the equations and carefully checking your calculations. Make sure you are using the correct values for the given variables and that you are using the equations correctly. If you are still having trouble, it may be helpful to seek assistance from a teacher or classmate to clarify any misunderstandings.

Remember, as a scientist, it is important to approach problems with a critical and analytical mindset. Take your time to carefully review all information and equations before attempting a solution. Good luck on your exam!