Electricity for public schools and colleges . will now befar greater than it was. When, as with the vibrator or other high speed interruptor, thedirect and inverse currents follow one another rapidly, the termi-nals / and / will show a permanent potential difference, owingto the difference in the of the two currents. We shallfind / to be —, and / to be -I-. This -A V is of course not reallyconstant, but is continually rising and falling. When, however,the currents follow one another with sufficient rapidity, the needleof a quadrant electrometer will give a deflexion indicative of theav
Electricity for public schools and colleges . will now befar greater than it was. When, as with the vibrator or other high speed interruptor, thedirect and inverse currents follow one another rapidly, the termi-nals / and / will show a permanent potential difference, owingto the difference in the of the two currents. We shallfind / to be —, and / to be -I-. This -A V is of course not reallyconstant, but is continually rising and falling. When, however,the currents follow one another with sufficient rapidity, the needleof a quadrant electrometer will give a deflexion indicative of theaverage A V between/ and/. CH. XXII. ARAGOS DISC AND RUHMKORFFS COIL 375 We saw in § 8 that the condenser acted not only to increase of the direct, but also to decrease the of theinverse, induced current Hence the condenser acts so as to in-crease the permanent -^ V between the secondary terminals. Coil used with Ley den jar.—If the two coatings of a Leyden jarare connected with m and n in the manner shown in the figure,. the discharge is modified in form. We do not now, as is the casewhen no jar is used, have a discharge each time that the breakis abrupt enough to give the required to overcome the air-space m n. On the contrary, the jar is charged only in virtue ofthe difference in between the two currents; and thedischarge across m n takes place only when the jar is sufficientlycharged; so that the period between two discharges depends uponthe capacity of the jar. The striking distance is very muchsmaller than when no jar is used ; and, for some reason whichthe present writer believes has not yet been made quite clear, itdepends further upon the capacity of the jar. Charging a Leyden jar battery.—The above given method maybe employed to charge a very large jar or battery. But where itis desired to charge such a battery and to leave it charged,another arrangement is adopted. Here the battery is charged bymeans of the direct current alone, a
Size: 2258px × 1107px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, bookpubl, booksubjectelectricity
