Hi

I am have trouble understanding the following question
View attachment question6_mosfetdiffamp.pdf
The book's answer has Rd=5-2/0.08=37.5k when i am finding Rd

however i got

Rd=10-2/0.08 = 100

what is my mistake?

P.S

 

your mistake is to call mosfet problem BJT (at least that is in the file name).

if the Vdd=+10V, Vo=2V and Id=80uA then Rd=(10-2)/(80*10^-6)=100k

 

fixed the thread title and file name

 

your mistake is to call mosfet problem BJT (at least that is in the file name).

if the Vdd=+10V, Vo=2V and Id=80uA then Rd=(10-2)/(80*10^-6)=100k

so is my book's answers wrong?

 

if that answer relates to that exact circuit then yes (and it would not be the first error in a textbook).

 

I have another question this time on part c, can someone explain to me why the dc load line in like the plot on the attachment.

View attachment question6_mosfetdiffamp_partc.pdf