When a short-circuit exists, how to find the current?

[jangchen]

Homework Statement

Find the Norton equivalent circuit of the circuit in Fig 4.45 at terminals a-b

Relevant Equations

When a short-circuit exists, current of other resistances with parallel is 0

I am not an English speaker, I apologize that I cannot use English well.

I have a question calculating the IN. When the terminal a-b is short-circuited, is it right that the currents are zero at 2 ohm and 6 ohm resistances?(Because they are parallel with a short-circuit.)

Also, because the current is zero at 2 ohm resistance, the Vx is zero. Is it right?

 

[BvU]

I can't think of any counter-arguments, so: yes, I think so !

 

[jangchen]

I can't think of any counter-arguments, so: yes, I think so !

Thank you for your answer!

 

[jbriggs444]

Also, because the current is zero at 2 ohm resistance, the Vx is zero. Is it right?

I would reason the other way around. If terminal a is shorted to terminal b then this forces the potentials at a and b to be equal. So $V_x$ is zero. It then follows that the current across the 2 ohm resistance is zero.

 

[jangchen]

I would reason the other way around. If terminal a is shorted to terminal b then this forces the potentials at a and b to be equal. So $V_x$ is zero. It then follows that the current across the 2 ohm resistance is zero.

wow I understand it thank you!