Picking the wrong resistor can literally burn your circuit, and in this video I show you how electrical engineers actually select resistors in industry—step by step. I walk through the real decision points people skip when they “just plug numbers into formulas”: package type (surface-mount chip resistors vs through-hole vs chassis mount), the product’s size constraints, and why form factor matters when you’re building something that has to be manufactured and assembled reliably. Then I jump into what I actually look at: the datasheet. I explain resistance in ohms, what tolerance really means (like 100 kΩ at 5% being 95 kΩ to 105 kΩ), and why different resistor materials and process control determine what a manufacturer can guarantee—and what it costs. We also talk about power rating and heat dissipation, because if your resistor is rated for 1/12 W and you push watts through it, it’s going to fry. Finally, I show the workflow side: sourcing considerations like in-stock status, RoHS, lifecycle/active parts, and having models (symbol, PCB footprint, 3D model) so you can drop the component into Altium and build a design that’s actually industry-ready.