Answer:
R2=25kΩ b) For 100kΩ c) R1=80kΩ and R2=50kΩ; R2=130 kΩand R1>130kΩ
Explanation:
For this question consider the circuit in the attachment
Vs-Vo=IR1
12=I(50000)
I=12/50 mA
Vo=IR2
6=(12/50)×R2
R2=25kΩ
b) For Resistances in parallel
Rt=(Rl×R2)/(Rl+R2)
For RL=300
Rt=23.08
Vo=Rt/(Rt+R1) ×Vs
Vo=5.68V
For RL=200
Rt=22.2
Vo=5.53V
For RL=100
Rt=20
Vo=5.14V
c) For Vo=6V, R1=2Rt
If R2=50kΩ and R1=80kΩ when RL=200kΩ
then Rt=40kΩ
and Vo=6V
Let's suppose R2=130kΩ and R1=130kΩ
Rt=(130×100)/(130+100)
Rt=56.52kΩ
Vo=56.52/(56.52+130) ×18
Vo=5.45V
Now if R1=130kΩ and R2=125kΩ
Vo=5.389V
Now if R1=125kΩ and R2=125kΩ
Vo=5.54V
So R1
So in order for Vo≥5.4V
R2=130 kΩand R1>130kΩ
