The 2SC5200 is a high power NPN Transistor with a collector to emitter voltage of 230V and collector current of 30A. The transistor is available in TO-264 package and is commonly used Amplifier designs.
The 2N547 is an age old JFET that was commonly used in Pre-Amp circuits. The JFET has VDS of 25V and VGS of 25V with a Gate current of 10mA. The FET also has high Input Impedance and Low Input Capacitance.
The BC337 is an NPN transistor with a maximum gain of 630, commonly used in low power audio applications. It can also switch loads upto 45V and 800mA hence also used as general purpose transistor.
The MMBT3904 is and SMD package NPN Transistor with VCE of 40V and a collector current of 200mA. It can be used as small signal switching transistor. It also has a low base voltage of 6V.
The TIP120 is a NPN Darlington Power Transistor. It can switch loads upto 60V with a peak current of 8A and continuous current of 5A. This makes it suitable for medium and high power electronics like controlling motors, solenoids or high power LEDs.
2N3055 is a general purpose NPN power transistor manufactured with the epitaxial base process, mounted in a hermetically sealed metal case. The device is designed for general purpose switching and amplifier applications.
2N2646 is general purpose silicon PN Unijunction Transistor that is designed for general purpose industrial applications. The device is popular as a triggering device and is not suited for driving power loads.
2N4403 is a general purpose PNP transistor used for low power switching and amplifier applications. The NPN complementary for the device is 2N4400, 2N4401.