Text Book on Wireless Telegraphy

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Longmans, Green, 1914 - Telegraph, Wireless - 344 pages

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Page 60 - ... circuit when the current is changing at the rate of one ampere per second and call this " The Coefficient of self-induction " or the " Inductance
Page 40 - X its resistance X time in seconds. In order that the student may become familiar with the methods of working electrical calculations, a few examples will now be given : — 1. A current of 5 amperes is required to drive a 100 volt motor; what is the power given to the motor, the total energy used in half an hour, and, if the efficiency of the motor is 80 per cent., what is its horse-power ? Power given to motor in watts = VC = 100 X 5 = 500 watts. Watts are joules per second, therefore energy used...
Page 31 - In this system of units the centimetre is the unit of length, the gramme is the unit of mass, and the second is the unit of time — hence the name — CGS units.
Page 15 - strength of a magnetic field" at any point is measured by the...
Page 70 - ... cycle and the number of cycles per second is called the frequency of the machine or circuit in which its current flows.
Page 60 - The coefficient of self-induction is measured in units called henrys— it a circuit has a "coefficient of self-induction "-of 1 henry, it means that when the current in the circuit is changing at the rate of 1 ampere per second there will be induced in that circuit an EMF of 1 volt. If the circuit consists of one turn of wire, the change of magnetic lines would in this case be 100,000,000 or 108 per second, if it consists of a coil of T turns the change in the number of 10* magnetic lines is -=-...

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