Transistor Current Relation — the NEET Physics formula with its derivation, variables, validity constraints and worked solver.
Transistor Current Relation Applicable to both NPN and PNP Bipolar Junction Transistors (BJTs) in all regions of operation (Active, Saturation, and Cut-off). Treat the transistor as a single point/junction in a circuit Apply the principle of conservation of charge Sum the currents entering and leaving the emitter, base, and collector regions Assumes steady-state conditions Neglects negligible surface leakage currents Kirchhoff's Current Law (KCL) must be satisfied at the transistor as a single node Thinking the Base current is larger than the Collector current Assuming the relation changes for NPN vs PNP transistors Forgetting that I E is always the largest of the three currents