Question

This circuit is a Wheatstone Bridge. It is used for numerous scientific and engineering applications. Here, R1 = 20 kΩ, R2 = 10 kΩ, R3 = 5 kΩ, and R4 = 10 kΩ. ε = 5 V.

a) Determine the Thevenin equivalent resistance RTH between points A and B. (Hint: when we remove the power supply and short the circuit, the wire connecting the “top” and “bottom” of the bridge can then be drawn to go right down the center of the bridge, from the top to the bottom. We can then can consider R1 and R3 to be in parallel to one another and R2 and R4 to be in parallel with one another.)

b) Determine the Thevenin equivalent voltage VTH between points A and B.

c) If R3 is a potentiometer (where the resistance can be changed), what would the resistance of R3 need to be set at to balance the circuit?

4 R, 2 R B A 3 R R ε

Answer 1

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Date... Page 20t 5 Valtese a ecss ヤ2.5V et aussume 5 V :5 V Thes thevenin Valto 1 5 an d ma c ve cen Drehies

Date... Paga whests tone balance 20)(10) to 2. Drehies