Why is emitter bias more stable than base bias?

 Transistor biasing is critical in an amplifier to make sure that the  transistor operates in a stable state without distortion of the signal.   Different bias configurations are used for different applications  depending on how you want the amplifier to operate.  One of the easiest  to implement is base biasing, what are some of the issues with base  biasing?  

answer the following:

  • Why is emitter bias more stable than base bias?
  • Explain why the base bias Q-point changes with temperature.
  • How does emitter-feedback bias improve on base bias?