Electricity: Its Theory, Sources, and ApplicationsE. & F.N. Spon, 1875 - 384 páginas |
Otras ediciones - Ver todas
Términos y frases comunes
ammonia anode armature arranged atoms attraction ball battery binding screw body carbon cathode charge chemical affinity chloride circuit coating coils condenser conductor connected copper current passes cyanide cyanide of potassium cylinder Daniell cell deflection deposit diameter direction disc dissolved earth ebonite effect electric current electro-magnet electrolysis electromotive force employed energy equal equivalent equivolt exactly fact fixed foot-pounds formulæ galvanometer give given glass grains guttapercha heat hydrogen inch inductive instrument insulated iron laws length Leyden jar liquid machine magnet matter measure mercury metal molecular molecules motion needle negative nitric acid object obtained ordinary oxygen paraffin plate platinum polarization polarized molecules poles principles produced quantity radicals ratio relation resistance salt set free shellac silver soldered solution substances sulphate sulphuric acid surface Table tension theory tricity tube unit varies veber vessel volts weight wire zinc وو
Pasajes populares
Página 152 - The entire connexion between the various units of measurement in this system may be summed up as follows. A battery or rheomotor of unit electromotive force will generate a current of unit strength in a circuit of unit resistance, and in the unit of time will convey a unit quantity of electricity through this circuit, and do a unit of work or its equivalent.
Página 19 - ... is determined by the equilibration of these two forces. If the atoms come too near, repulsion predominates and drives them apart ; if too distant, attraction predominates and draws them together. The point at which attraction and repulsion are equal to each other is the atom's position of equilibrium. If not absolutely cold— and there is no such thing as absolute coldness in our corner of nature — the atoms are always in a state of vibration, their vibrations being executed to and fro across...
Página 19 - ... members of this group part company ? The molecules do separate from each other when the external pressure is lessened or removed, but the atoms do not. The reason of this stability is that two forces, the one attractive and the other repulsive, are in operation between every two atoms...
Página 277 - ... sediment is left, destitute of any adhesive property ; on putting a quantity of this sediment into a pot nearly filled with melted pitch, a violent effervescence will take place, setting free a volume of white fumes having a creosotic smell. After all effervescence has ceased, which will not be before a considerable time, and when all the mass seems to have been acted upon, the process of making an excellent protecting coating is completed — a coating which will not yield in the solution, and...
Página 360 - ... cores, and electrolysis being instantaneous, it is obvious that the lever will respond to signals transmitted with great rapidity. I have succeeded in transferring signals from one circuit to another at the rate of 650 words per minute; hence it may be used to repeat the rapid signals of the automatic telegraph into secondary circuits. By attaching an ink wheel to the extremity of the lever, opposite a continuous strip of paper moved by clockwork, messages transmitted at a speed of several hundred...
Página 154 - We are told that it is for a similar cabalistic reason electricians employ the term " potential." Not understanding the term, and yet finding it necessary to say something about it, this is how the author discusses the subject : " The word [potential] is always used in place of tension or electro-motive force, because there is something full and smooth sounding about it ; but the idea which really does belong to it is a pure mathematical abstraction which only highly trained minds can apprehend "...
Página 151 - The unit of electro-chemical intensity is the force of the current, which, in a unit of time, decomposes a unit of weight of water, or an equivalent quantity of any other electrolyte. c. The unit of electro-magnetic force, is the force of a current which — when it traverses a circular conductor whose sectional area is equal to the unit of surface, and acts upon a magnet whose magnetic moment is equal to unity, the magnet being placed at a great distance, and in such a manner that its axis is parallel...
Página 342 - The form of the iron influences its suspensive power. Cylinders carry greater weights than rectangular bars ; and a hollow cylinder from which a portion has been cut away, so as to form a long horse-shoe magnet when viewed in the direction of its axis, but a very short one if taken as to its height, is capable of receiving a very great suspensive force ; and lastly, a slight curvature of the polar surface adds considerably to its power.
Página 342 - The free magnetism at any given transverse section of a magnet is proportional to the difference between the square root of half the length of the magnet and the square root of the distance between the given section and the nearest end. — (Dub.) xv.
Página 154 - Difference of potentials is a difference of electrical condition in virtue of which work is done bj positive electricity in moving from the point at a higher potential to that at a lower potential, and it is measured by the amount of work done by the unit quantity of positive electricity when thus transferred.