. The Ontario high school physics. ough the spaceinclosed by the coil C\ is decreasing, and a direct (clockwise)current is induced in it. 2. The number of lines of force through the coil C^ isincreasing, and an inverse (contra-clockwise) current is inducedin it; but as the coils present opposite ends when viewed fromiV, it is evident that the current flows in the same absolutedirection in C^ and Co. 3. The number of lines of force through the coil 63 isdecreasing, and a direct (clockwise) current is induced in it. 4. The number of lines of force through the coil C^ isincreasing, and an inverse
. The Ontario high school physics. ough the spaceinclosed by the coil C\ is decreasing, and a direct (clockwise)current is induced in it. 2. The number of lines of force through the coil C^ isincreasing, and an inverse (contra-clockwise) current is inducedin it; but as the coils present opposite ends when viewed fromiV, it is evident that the current flows in the same absolutedirection in C^ and Co. 3. The number of lines of force through the coil 63 isdecreasing, and a direct (clockwise) current is induced in it. 4. The number of lines of force through the coil C^ isincreasing, and an inverse current (contra-clockwise) is inducedin it; but as C3 and C^ present opposite ends when viewedfiom iV, the currents flow in the same absolute direction ineach, but in a direction opposite to that in the coils C^ and ,. Similarly with any number of coils, the currents in all coils onone side of the line AB flow in one direction while those, in thecoils on the other side of AB flow in the opposite direction. 448 INDUCED CURRENTS. Fig. 543.—Modern direct-current dynamo. A, Drumarmature ; B, multipolar field ; C, dynamo complete. Hence, it tlie eiuls of tlu^ wires oi the coils are connected totlie coininutator plates, and the brushes bear upon these platesat the points E and F as shown in the figure, a direct, orcontinuous, current will flow from F to E through a conductor which joins the action in a drumarmature is similar. Thecoils are so wound thatthe currents on bothsides flow in the arma-ture away from onebrush and to the otherbrush. It is obvious that ina multipolar field, theremust be as many pairsof collecting brushes asthere are pairs of poles. Fig. 543 shows a modern direct-current dynamo with drum armature and multipolar field. 530. Excitation of Fields in a Dynamo. In the alternating-current dynamo the electromagnets which form the fields aresometimes excited by a small direct-cur-rent dynamo belted to the shaft of themachine (see also Fig. 539); in th
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Keywords: ., bookcentury1900, bookdecade1910, bookpublishe, booksubjectphysics
