Analog Electronics - Engineering

Q1:

A Darlington pair has β = 300. If RE = 1 kΩ and RL = 100 Ω, the input impedance at the base is approximately

A 300 k ohm

B 3 k ohm

C 100 k ohm

D 30 k ohm

ANS:B - 3 k ohm

What is the formula for solving this problem?