TS EAMCET 5 May 2018 Shift 2 Solved Paper

Consider the expression for I .
I=7.8×10−5e6.9vD
Differentiate the above equation with respect to VD

d

dVD

(I)=

d

dVD

(7.8×10−5e6.9VD)
=7.8×10−5×6.9×e6.9vD
=I×6.9
The dynamic resistance is given as,

dVD

dI

=

1

6.9×I

Here, On substituting the values as I=4mA=4×10−3A.
We get,

dVD

dI

=

1

6.9×4×10−3

=36.23Ω
Thus, the dynamic resistance is 36.23Ω.