In non-inverting amplifier, the input voltage V1 is feed to non-inverting input terminal. The current I1 through the resistance R1 is given by
I1 = VB/ V1
The current through the feedback resistor R0 is given by
Vout = 1+ R1
Where gain of the non-inverting amplifier is
The gain depends upon the resistance R1 and R0. The input impedence of the amplifier is very high as practically no current flows through the input source V1.