2N3055 general use TO-3 casePower 115W/60V maxDatasheet here
Small signal transistor BC547B
BS170
BS250
IRF540N N-channel . HEX mosfet general use TO-220 casePower 130W/100V maxDatasheet here
IRF740 N-channel . HEX mosfet general use TO-220 casePower 125W/400V maxDatasheet here
IRF840 N-channel . HEXfet general use TO-220 casePower 125W/500V maxDatasheet here
Small signal transistor is used for general purpose control of signal or switch. Case TO-92 in plastic (as in picture).
TO18 is of metal (2N2...More info
