Recent content by Jason7fd

I wish I was taught about this in school but they are not in the syllabus. It is a question from O-level Physics of Malaysia.

I hav updated the schematic diagram. Sorry, I am not sure what are BJT and forward-active mode. The value of R2 is not provided in this question.

Homework Statement http://img300.imageshack.us/img300/2640/17569077cy5.jpg The transistor is a N-P-N type. When the siren is functional, the resistance of thermistor is 120 ohm. R1 is 600 ohm. The question is "Calculate the collector current if the emitter current is 100mA". I know that...