In order to light up the LED, what should Pin 1 and Point B connected to? Ans: Pin I connected to (5V / GND), Point B connected to (5V / GND) In this example, the power that lights up the LED comes from where? Ans: Power comes from 74LS04 Pin 1 Point B 3300 Pin 2 Now, use a multi-meter to measure the current. Please note the +ve and -ve terminals of the multi- meter, 74LS04 Pin 1 Point B 3302 Multi-meter Pin 2 What is the current shown on the multi-meter? Is the current flowing out from Pin 2 or flowing into the Pin 2? Ans: Current shown on multi-meter: Direction: (out from / into) Pin 2 Now, try to directly connect pin 2 through the multi-meter to Point B, measure the current again. Is the current flowing out from Pin 2 or flowing into the Pin 2? 74LS04 Pin 1 Point B Multi-meter Pin 2 Ans: Current shown on multi-meter: Direction: (out from / into) Pin 2