 The Q-point is typically near the middle of the DC load line, so as to obtain the maximum available peak-to-peak signal amplitude without distortion due to clipping as the transistor reaches saturation or cut-off.The process of obtaining an appropriate DC collector current at a certain DC collector voltage by setting up the operating point is called biasing.Grid bias is the DC voltage provided at the control grid of a vacuum tube relative to the cathode for the purpose of establishing the zero input signal or steady state operating condition of the tube.