An elementary book on electricity and magnetism and their applications . Fig Single loop of wire turning in a mag-netic field. ELECTROMAGNETIC INDUCTION 143 wire AD is moving up, and the current tends to flow fromA to D. The result is that during the first half turn the cur-rent goes around the loop in the direction ADCB. During thesecond half turn the current is reversed and goes around in thedirection A BCD. To show that this really does happen in the loop, we can cutthe wire and connect the ends to slip rings x and y (Fig. 88). The brushes B and B, whichrest on the rings, are connectedto a
An elementary book on electricity and magnetism and their applications . Fig Single loop of wire turning in a mag-netic field. ELECTROMAGNETIC INDUCTION 143 wire AD is moving up, and the current tends to flow fromA to D. The result is that during the first half turn the cur-rent goes around the loop in the direction ADCB. During thesecond half turn the current is reversed and goes around in thedirection A BCD. To show that this really does happen in the loop, we can cutthe wire and connect the ends to slip rings x and y (Fig. 88). The brushes B and B, whichrest on the rings, are connectedto a galvanometer. In thisway it can be shown that there. Fig. 88. — Coil rotating between poles of electromagnet and a single loop con-nected to slip rings. is generated in the coil an alternating current, which reversesits direction twice in every revolution. Moreover, it will beseen that the induced starting at zero goes up to a maxi-mum and then backto zero in the firsthalf turn; then itreverses, goes to amaximum in the op-posite direction andfinally back to zero. LL~^ P0SITI0N 0F L00P1N DEGREES rpii -it r Fig. 89. — Curve to show relation of induced The induced to position of loop, reaches its maxi-mum when the coil is horizontal, because in this position thewires AD and BC are cutting lines of force most rapidly. Thisis illustrated by the curve shown in figure 89. Machines which
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectmagnetism, bookyear19
