A current source can only affect a voltage when there is a resistance involved.

 

A current source can only affect a voltage when there is a resistance involved.

aRE YOU sure? I just simulated with LTspice with and without that current source regardless of a resistance and the voltage shows different results. By using common sense I think it is also different., right?

 

The current source will develop whatever voltage across it is needed to cause the specified current to flow. An ideal current source can have either a drop or an increase across its terminals. Most practical current sources can only introduce a voltage drop.

 

A current source can only affect a voltage when there is a resistance involved.

you mean that, only with a resistance in the branch of the current source 5mA, Voltage at node A is affected, and without a resistance , Voltage at node A is different, is that what you mean?

 

aRE YOU sure? I just simulated with LTspice with and without that current source regardless of a resistance and the voltage shows different results. By using common sense I think it is also different., right?

That is because you are using a perfect diode. It always has a voltage drop of 0.7V, regardless of the current.
Real diodes have resistance.

 

So, now go back to the circuit and look at it from a different point of view. A few minutes spent now fully understanding it will save hours later.
The cathode of D1 is connected to ground. What is the voltage on the anode?

 

That is because you are using a perfect diode. It always has a voltage drop of 0.7V, regardless of the current.
Real diodes have resistance.

no, now forget diodes in 2 branches, you replace them with normal resistors and check your statement again '' A current source can only affect a voltage when there is a resistance involved. ''

 

So, now go back to the circuit and look at it from a different point of view. A few minutes spent now fully understanding it will save hours later.
The cathode of D1 is connected to ground. What is the voltage on the anode?

no more checks?!