Question

X X x x X X x x X X X X X x x X X X x x 11.3) The figure on the right illustrates a horizontal conducting bar which is slideably attached to a stationary U- shaped conducting section having a width L. The horizontal bar has mass M and resistance R and the U-shaped section is a perfect conductor. The horizontal bar can slide without friction along the vertical sides of the U-shaped section while maintaining contact. The bar is a vertical distance y above the horizontal base of the U-shaped section. In the absence of a magnetic field, the bar would accelerate downward at a rate g. However, a spatially uniform time-dependent magnetic field extending perpendicularly through the page x x x prevents the bar from moving. The only forces acting on the bar are either gravitational or magnetic. Determine the time- dependent function, B(t), representing the magnetic field such that B(t) is positive if the magnetic field is directed into the page and B(t=0) = Bo. The function should include necessary terms from the list {t, Bo, M, R, Y, L, and g} X

Answer 1

dt magnetic force = weight FB = Mg --- flux +) = BCH) x area = BCH) YL magnitude of induced emf, e=do(4) = YL dB(A) indeed current, és enyhe d2017 Magnetic force, FB = iL BA- YŁ 84) decem e from 0 & The Blue) dee – Mg. at YL r Bean Mar / BCH) dBH) = ct BCA) 230 - dh mga BO 0 A R (84) - 8)] = + given B(0) = Bo in (BH)) ² - 8 = 2 mgh it YL