The magnet ' is wound to a resistance of amperes with accumulators).
By Ohm'S Law, And By The Definition Of Difference Of Electric Pressure Or Potential, We Obtain The Following Alternative Expressions For The Quantity Of Heat H In Joules Generated In A Time T Seconds By A Current Of C Amperes Flowing In A Wire Of Resistance R Ohms, The Difference Of Potential Between The Ends Of The Wire Being E = Cr Volts: H=Ect=Crt=E Z T/R.
He enclosed various metallic junctions in a Bunsen ice calorimeter, and observed the evolution of heat per hour with a current of about 1.6 amperes in either direction.
Currents from the ten-thousandth of an ampere to ten thousand amperes, electrical pressures from a minute fraction of a volt to 100,000 volts, come within the range of his instruments, while the private consumer of electric energy is provided with a meter recording Board of Trade units.
The instrument therefore does not begin to read from zero current, but from some higher limit which, generally speaking, is about one-tenth of the maximum, so that an ammeter reading up to io amperes will not give much visible indication below i ampere.