TRANSISTOR AS A SWITCH

DEAR STUDENTS,

PLEASE do this topic for pre board exam .


The transistor always remains in CUTOFF OR SATURATION MODE.In case of silicon the energy gap is 0.6 volt.If the transistor is in cut off mode the collector current is zero.When the input voltage is more than this value the transistor is in active mode & output voltage decreases as the contribution of ICRC INCREASES.tHE OUTPUT voltage decreases linearly till its value is less than about 1volt.After this the change becomes non linear & transistor goes to saturation mode.SO low input means OFF & HIGH INPUT MEANS ON.(REFER TO N.C.E.R.T PAGE 496)