Popular transistors.

BC178 transistor.
Pinout. Datasheet.

Marking: BC178.
Package: TO-18, 1-emitter, 2-base, 3-collector.
Material of transistor: Si
Polarity: PNP
Total Devise power dissipation |PD|: 0.3 W(at ambient temperature + 25 °)
Collector-base breakdown voltage |VCBO|: 30V
Collector-emitter breakdown voltage |VCEO|: 25V
Emitter-base breakdown voltage |VEBO|: 5V
Maximum collector current |Ic max|: 100mA
Maximum junction temperature |Tj|: +175°C
Transition frequency (ft) : 100MHz(min), 200MHz(typ.)
Collector Capacitance|Cc |:6pF
Collector-emitter saturation voltage|VCE|:300mV(IC=10mA,IB=0,5mA),
250 mV(IC=100mA,IB= 5mA).
Base-emitter saturation voltage|VBE|:700mV(IC=10mA,IB=0,5mA),
850 mV(IC=100mA,IB= 5mA).
Forward current transfer ratio |hFE| : 125-500(IC=2mA,VCE=5V),125-260(BC178A), 240-500(BC178B).