This is an image demonstrating the use of a pull up resistor.
I've just started studying electronics and have been learning about ohm's law. Ohm's law says that current within a circuit is equal to the potential drop across that circuit (or section of circuit) divided by the resistance of that circuit.
I understand that the pull up resistor prevents a short and limits current flow; however I am confused about how pressing the switch actually changes the current being delivered to the control chip. The circuit of the control chip (coming down from the top and exiting at the right) still has the same voltage drop and still has the same resistance regardless of whether the switch at the bottom is open or close. According to Ohm's Law this means that the current should be unaffected.
I'm sure there is an error in my logic, however I'm having difficulty figuring out where. I appreciate the help!