Challenges:
 Set R1 = 20 and R2 = 40. Predict the value of R3 required to cause Vo = 20. Use the scrollbars to check your prediction.
 Set R1 = 20 and R2 = 40. Determine the range of output voltage that can be obtained by adjusting the resistance R3.
 Set R1 = 25 and R3 = 40. Predict the value of R1 required to cause Vo = 30. Use the scrollbars to check your prediction.
 Set R1 = 25 and R3 = 40. Determine the range of output voltage that can be obtained by adjusting the resistance R2.
 Set R3 = 50. Determine the range of output voltage that can be obtained by adjusting the resistances R1 and R2.
 Determine the range of output voltage that can be obtained by adjusting the resistances R1, R2 and R3.
 Adjust R1, R2 and R3 so that Vo = 25.
 Adjust R1, R2 and R3 so that Req = 25.
 Adjust R1, R2 and R3 so that Req = 60.
