Match the following.

Group - I

(a)Cascode amplifier
(b)Differential Amplifier
(c)Darlington pair common-collector Amplifier

Group - II

(1)does not provide current gain
(2)is a wide band Amplifier
(3)has very low input impedance Emitter Amplifier and very high current gain
(4)has very high input impedance and very high current gain
(5)Provides high common mode voltage Rejection

A Darlington stage is shown in the figure, if the transconductance of q₁ is g_m1 and q₂ is g_m2, then the overall transconductance
$$g\matrix{ c \cr m \cr } \left[ { \buildrel \Delta \over = {{{i_c}^c} \over {{v_{be}}^c}}} \right]$$ is given by

If the transistors in fig. has high value of β and a v_BE of 0.65, the current I flowing through the 2 kilo ohms resistance will be ______.

In figure, all transistors are identical and have a high value of beta. The voltage VDC is equal to ______.