How sensitivity is controlled by vertical amplifier of a cathode ray oscilloscope?
The vertical amplifier drives the vertical deflection plates of the CRT which cause the electron beam to be deflected by an amount proportional to the voltage applied to the deflection plates. The input signal applied to the vertical amplifier gets amplified and causes the deflection to be proportional to the instantaneous input voltage. The amplifier is calibrated and has multiple gain settings so that the amount of input voltage required to cause a unit (normally 1 cm) deflection is controlled usually by a knob on the front panel.
