The Current, I Ampere flowing through wire is inversely proportional to resistance, R Ohms. Given that current of 12 Ampere has resistance of 0.5 Ohms, find: i-The resistance when current is 3 Amperes.
ii-Relation between current and resistance
iii-The current when resistance is 3 Ohms.​​

Asteel tube (k=50 w/mk) of inner and outer diameter di = 20mm and do=26mm, respectively, is used to transfer heat from hot gases flowing over the tube (h-hot = 200w/m2k) to cold water flowing through the tube (h-cold = 8000 w/m2k). what is the cold-side overall heat transfer coefficient uc? to enhance heat transfer 16 straight fins of rectangular profile are installed longitudinally along the outer surface of the tube. the fins are equally spaced around the circumference of the tube, each having a thickness of 2mm and a length of 15mm. what is the corresponding overall heat transfer coefficient uc? *solve for uc in both cases*