I am pretty new to the world of electronics so apologize yet again for a very basic question.
I am trying to understand the functioning of a transistor, but my confusion may underpin some more fundamental confusion about voltage. I think understanding this circuit will help me grok the fundamentals.
When the button is closed like in picture, the light is off. I actually built it and verified that when it's closed, the voltage between base and emitter is actually zero, and the voltage across the 1k resistor is around 0.8V. I also found that when increasing this resistance to around 5k or more, the transistor is on whether the button is pressed or not.
I do not understand why is the voltage 0 at the base and why it's always on when the bottom resistor increases. The explanation in the text doesn't make sense. Could anyone help me understanding this? Thanks