A level physics teachers- a bit of help please! Anyone know why D is the answer here?! (My calculation gives 17.7%...) @ChatPhysics #ChatPhysicsLive #ASEChat
@mrgrints @ChatPhysics r = (emf - terminal pd) / current. Abs uncertainty of the bit in bracket is sum of Abs uncertainties of them (because of minus), so (emf - terminal pd) = 1.5 +-0.3 which is +-20%. Current is 5%. Then it's a divide so you combine the percentage uncertainties.
@mrgrints @ChatPhysics Pluses and minuses you combine the absolute uncertainties because they have the same units so can be summed. Multiply and divides you have to combine the percentage uncertainties because your using the percentage to remove the units, so then they can be summed.
@mrgrints @ChatPhysics Hi, out of interest where would this question be from? I'm always on the hunt of good uncertainties questions!
@mrgrints @ChatPhysics This man needs to come back absolute W chad found in the wild
@mrgrints @ChatPhysics It’s been a whole year since his last post…