Since this is a new topic, you should really start a new thread.Question.
A non-inverting amplifier has a voltage gain of 5. If the value of the feedback resistor is 12kΩ what must the value of R1 be?
A. 7kΩ
B. 6kΩ
C. 4kΩ
D. 3kΩ
E. None of the above
in order for me to find R1, do i rearrange the forum?
voltage gain=5
5= 1+ Rf/R1
5-1=12Ω/R1
4=12Ω/R1
but this is where i mess up.
R1=12Ω*4=48Ω
but if i did 12/4= 3Ω which is one of the Options!
Where did i mess up
You're good until you say you have a problem at:
4 = 12Ω / R1
Multiply both sides by R1 gives
4 * R1 = 12Ω ----> R1 / R1 is equal to 1
Now divide by 4
R1 = 12Ω / 4 ----> 4 / 4 gives 1
and find your answer.