The Standard Electrical Dictionary Part 91

It is a key which slides along over the wire and which, when depressed, presses a platinum tipped knife edge upon the wire. On being released from pressure the key handle springs up and takes the knife edge off the wire. This removal is essential to avoid wearing the wire, whose resistance per unit of length must be absolutely uniform.

Key, Telegraph.

The key used in telegraphy for sending currents as desired over the line. It consists of a pivoted lever with finger piece, which lever when depressed makes contact between a contact point on its end and a stationary contact point on the base. This closes the circuit through the line. When released it springs up and opens the line circuit.

Kilo.

A prefix to the names of units; it indicates one thousand times, as kilogram, one thousand grams. A few such units are given below.

Kilodyne.

A compound unit; one thousand dynes. (See Dyne.)

Kilogram.

A compound unit; one thousand grams; 2.2046 pounds avds.

317 STANDARD ELECTRICAL DICTIONARY.

Kilojoule.

A compound unit; one thousand joules, q. v.

Kilometer.

A compound unit; one thousand meters; 3280.899 feet; 0.621382 statute miles. (See Meter.)

Kilowatt.

A compound unit; one thousand watts, q. v.

Kine.

An absolute or C. G. S. unit of velocity or rate of motion; one centimeter per second; proposed by the British a.s.sociation.

Kirchoff's Laws.

These relate to divided circuits.

I. When a steady current branches, the quant.i.ty of electricity arriving by the single wire is equal to the quant.i.ty leaving the junction by the branches. The algebraical sum of the intensities of the currents pa.s.sing towards (or pa.s.sing from) the junction is equal to zero; Summation(C) = 0 (Daniell.) In the last sentence currents flowing towards the point are considered of one sign and those flowing away from it of the other.

II. In a metallic circuit comprising within it a source of permanent difference of potential, E, the products of the intensity of the current within each part of the circuit into the corresponding resistance are, if the elements of current be all taken in cyclical order together, equal to E; Summation(C * r) =E. In a metallic circuit in which there is no source of permanent difference of potential E = 0, and Summation(C *

r) = 0.

This law applies to each several mesh of a wire network as well as to a single metallic loop, and it holds good even when an extraneous current is pa.s.sed through the loop. (Daniell.)

In this statement of the two laws E stands for electro-motive force, C for current intensity; and r for resistance of a single member of the circuit.

[Transcriber's note: These laws may be restated as: At any point in an steady-state electrical circuit, the directed sum of currents flowing towards that point is zero. The directed sum of the electrical potential differences around any closed circuit is zero.]

Knife-edge Suspension.

The suspension of an object on a sharp edge of steel or agate. The knife edge should abut against a plane. The knife edge is generally carried by the poised object. Its edge then faces downward and on the support one or more plane or approximately plane surfaces are provided on which it rests. In the ordinary balance this suspension can be seen. It is sometimes used in the dipping needle.

It is applied in cases where vertical oscillations are to be provided for.

Knot.

The geographical mile; a term derived from the knots on the log line, used by navigators. It is equal to 6,087 feet.

Synonyms--Nautical Mile--Geographical Mile.

[Transcriber's note: A knot is a velocity, 1 nautical mile per hour, not a distance. The contemporary definition is: 1 international knot = 1 nautical mile per hour = 1.852 kilometres per hour = 1.1507794 miles per hour = 0.51444444 meters per second = 6076.1152 feet per hour.]

318 STANDARD ELECTRICAL DICTIONARY.

Kohlrausch's Law.

A law of the rate of travel of the elements and radicals in solutions under the effects of electrolysis. It states that each element under the effects of electrolysis has a rate of travel for a given liquid, which is independent of the element with which it was combined. The rates of travel are stated for different elements in centimeters per hour for a potential difference of one or more volts per centimeter of path.

[Friedrich Wilhelm Georg Kohlrausch (1840-1910)]

Kookogey's Solution.

An acid exciting and depolarizing solution for a zinc-carbon couple, such as a Bunsen battery. Its formula is: Pota.s.sium b.i.+.c.hromate, 227 parts; water, boiling, 1,134 parts; while boiling add very carefully and slowly 1,558 parts concentrated sulphuric acid. All parts are by weight.

Use cold.

Krizik's Cores.

Cores of iron for use with magnetizing coils, q. v. They are so shaped, the metal increasing in quant.i.ty per unit of length, as the centre is approached, that the pull of the excited coil upon them will as far as possible be equal in all positions. A uniform cylinder is attracted with varying force according to its position; the Krizik bars or cores are attracted approximately uniformly through a considerable range.

L.

Symbol for length and also for the unit of inductance or coefficient of induction, because the dimensions of inductance are length.

Lag, Angle of.

(a) The angle of displacement of the magnetic axis of an armature of a dynamo, due to its magnetic lag. The axis of magnetism is displaced in the direction of rotation. (See Magnetic Lag.)

(b) The angle expressing the lag of alternating current and electro-motive force phases.

Laminated. adj.

Made up of thin plates, as a laminated armature core or converter core.

Lamination.