Question 19.7: Find Zth for the part of the circuit in Figure 19-18 that is...

Find Z_{th} for the part of the circuit in Figure 19-18 that is within the beige box as viewed from terminals A and B. This is the same circuit used in Example 19-4.

The Blue Check Mark means that this solution has been answered and checked by an expert. This guarantees that the final answer is accurate.
Learn more on how we answer questions.

First, replace V_{s} with its internal impedance (zero in this case), as shown in Figure 19-19. Looking in between terminals A and B. R_{1} and X_{L}are in parallel. Thus.

Z_{th}=\frac{(R_{1}\angle 0°)(X_{L}\angle 90°)}{R_{1} + jX_{L}} = \frac{(100\angle 0°\Omega) (50\angle 90°\Omega)}{100 \ \Omega + j50 \ \Omega }

 

\ \ \ \ \ \ =\frac{(100\angle 0°\Omega) (50\angle 90°\Omega) }{112\angle 26.6°\Omega} =44.6\angle 63.4°\Omega
Screenshot (921)

Related Answered Questions