You could, of course, take any other length of any size as your standard, but it will be best to make your coils with a certain number of Ohms resistance.
The figures between them show how many Ohms resistance there are in the coil above.
The figures given by Jenkin have, however, been reduced to international ohms and C.
A) Take the reading of G V with 2 ohms resistance in the lower branch; that is, with the whole of R C in circuit.
It is so arranged that either one or two ohms can be used at will.
It will be found, upon trial, if we put a resistance of 2 ohms in place of R, Fig.
When 2 ohms resistance are wanted, let the current enter at L and leave at R (or the reverse).
One of these taps is usually 50 ohms distant from the end terminal and the other only 5 ohms from the end.
The resistance of R{1} in ohms should be rather more than ten times the voltage of the circuit, so that a current of a little less than .
The function of the short length of resistance rod CD is as follows: It has an ohmic resistance of about 30 ohms but is non-inductive.
This resistance is usually about 100 ohms per volt capacity of the meter, and is composed of fine silk covered copper wire wound non-inductively on a wooden spool.
Track relays with resistances of 2 and 4 ohms are usually employed.
The scale of the instrument is arranged in two parts, one of which indicates ohms and the other is divided into uniform divisions for use when locating crosses and grounds by the Murray and Varley loop methods.
In the above table to reduce, for instance, British Association ohms to International ohms, multiply by .
It consists of a portable slide wire, Wheatstone bridge arranged to read directly in ohms in addition to its use for locating crosses and grounds.
Then, the total resistance is to the 1,000 ohms shunt resistance as .
This coil usually has a resistance of about 75 ohms and the meaning of the ohmic resistance of a receiver and its bearing on the sensitiveness of it will be explained a little farther along.
A rheostat that has a resistance of 6 ohms and a current carrying capacity of 1.
Then again the higher the resistance of the receivers the more sensitive they often are and those wound to as high a resistance as 3,200 ohms are made for use with the best sets.
Take, for instance, two branches of 100 ohms resistance each and find the joint resistance.
Applying Ohm's Law here, we find thatohms resistance equals volts divided by amperes, or R = 110/7.
A Bradley tangent galvanometer is used, employing the coil of 160 ohms resistance.
In each multiplier wire I have 500 ohms resistance.
Should the bolt so arranged be required to be fired at will, it is only necessary to put a more powerful battery in circuit, and so fire the fuze through the 20 ohms resistance.
The air gap between the carbon pencils would have a resistance of many thousand ohms if it were not for the presence of the carbon vapour.
I will drop a few crystals of it into a tumbler of water and dip in two carbon pencils connected to the dynamo current, using between fifty and sixty ohms of resistance in the circuit so as to have two amperes flowing.
The distance from the mill to the cottage is one mile, and the complete circuit therefore would require two miles of wire, or four ohms of resistance.
They want 20 amperes and the line offers 4 ohms of resistance.
At the temperature of bright incandescence their resistance may be increased as much as fivefold and sometimes becomes about ten ohms to the inch.
Well," I said, "whether you feel anything or not one-thousandth of an ampere is passing through your tongue and you are offering fifteen hundred ohms of resistance.
This makes a total of 750 ohms for the secondary circuit.
The wire in this iron we found to offer about 28 ohms resistance when hot, and it lets pass 4 amperes.
It contains about two hundred and twenty ohmsof resistance and requires the same current as a 16-candle-power lamp.
A pair of magnets of about 50 ohms are mounted on this support.
Obviously, the resistance of twenty ohms is entirely independent of the length of the line, all the other factors being constant, and wires of various sizes will be required for other distances of transmission.
This constant factor is always the same for any given material, as pure iron, copper, or aluminum, and is usually taken as the resistance in ohms of a round wire one foot long and 0.
In order to use the formula for any desired metal, it is necessary that the resistance in ohms of a round wire of that metal one foot long and 0.
This can be done by substituting in the formula, amperes = volts ÷ ohms, the expression for the number of ohms in any conductor, and then solving as before.
It is as well to begin with a fair resistance, say 100 ohms out in the box, and the progress of the deposit is watched by means of a low-power microscope set up in front of the thread.
Ordinary iron telegraph-wire measures about thirteen ohms to the mile.
The unit of resistance, as mentioned in the last chapter, is called the ohm, and the more ohms there are in a wire as compared with another, the more volts we have to put into the battery to get the same current.
The first two wires constructed gave only two ohms resistance to the mile, which facilitated the experiments.
Hence, to reduce British Association ohms to International ohms, divide by 1.
Thomson recorder circuit, or a resistance of 1½ ohms per cell; but if only occasionally used, the same quantity of solution will last several weeks.
All wires have a certain resistance per foot, according to the nature of the metal used and the size of the wire--that is to say, the finer the wire the greater number of ohms resistance it has to the foot.
What current will flow through a bell circuit of 8 ohms resistance if it contains three cells in series each with an E.
How far away is the break in the wire if the latter has a resistance of 80 ohms to the mile?
How many feet should be used in winding a 200 ohms relay?
A resistance-box usually contains coils of platinum-silver wire of from five thousand ohmsdownwards to single ohms or fractions of an ohm.
The leak should have a very high resistance, usually one or two million ohms if the condenser is about 0.
In the first place the primary of the transformer has a number of ohms just equal to the internal resistance of the tube.
How manyohms would the coil have if it took 5 volts to send 2 amperes through it.
For 3 ohms it takes three times as much to give one ampere.
Divide the number of volts by the number of amperes and the quotient (answer) is the number of ohms of resistance in the coil.
If it has a million ohms we say it has a "megohm" of resistance.
At the same time you can buy four resistance spools of one hundred ohms each and perhaps one of 500 ohms.
If a coil of resistance three ohms is carrying two amperes what is the voltage across the terminals of the coil?
Notice that I told the number of ohms and the number of volts, what are you going to tell?
You can assemble a resistance which will do fairly well if you will buy a small rheostat which will give a resistance varying by steps of ten ohms from zero to one hundred ohms.
When the contact T is open, the current flows through the plunger in series with 2,600 ohms resistance.
The sensitiveness is so great that it is desirable to introduce a resistance of some 500 ohms into the thermal-junction circuits.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "ohms" in a variety of sentences. We hope that you will now be able to make sentences using this word.
