How would you be able to vary flux linkage in a linear fashion if it depends on theta? Like if you rotate the field at a constant angular speed somehow, wouldn't the graph of flux linkage vs time be a cosine graph instead of a straight line like at 7:17?
Apologies for the v late reply. You are right, but the worked example is about calculating the average induced emf, so graphically we can draw a linear graph (regardless of whether the flux linkage vs time graph is a cosine or whatever) and its gradient will give the average emf. In principle, if the angular speed could be varied with time in a precise manner, the flux linkage could vary linearly with time.
Going through worked examples helps to accelerate understanding. Great video!
Agreed :) Thanks for the kind words!
How would you be able to vary flux linkage in a linear fashion if it depends on theta? Like if you rotate the field at a constant angular speed somehow, wouldn't the graph of flux linkage vs time be a cosine graph instead of a straight line like at 7:17?
Apologies for the v late reply. You are right, but the worked example is about calculating the average induced emf, so graphically we can draw a linear graph (regardless of whether the flux linkage vs time graph is a cosine or whatever) and its gradient will give the average emf.
In principle, if the angular speed could be varied with time in a precise manner, the flux linkage could vary linearly with time.