## General theory and practice |

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adjusted aerial circuit alternating current ammeter amperes apparatus armature arrangement atom battery buzzer capacity effect cell closed circuit conductor connected in series consists copper crystal crystal detector current flowing curve damping decrease decrement depends detector and telephones detector circuit dielectric difference of potential direction disc discharge earth ebonite electric strain electrons ether strain ether waves glass increase inductance effect induction coil insulated iron J. J. Thomson joined in series magnetic field magnetic lines magnetic strain Marconi Marconi Company mast metal metres natural wave length obtained ohms oscillating circuit oscillating currents oscillations oscillatory plates poles potentiometer receiver aerial receiver circuit resistance resonance secondary circuit sensitive shown in Fig shunt signals solution spark gap stations strain effects surface switch takes place Telefunken telephone receivers terminals transformer transmitter tube tuning coil undamped unit valve variable condenser vibration voltage volts watts wave length wavemeter wire wireless zero

### Popular passages

Page 75 - 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 -=-...

Page 156 - Any force such as OM can be resolved into two components at right angles to each other...

Page 6 - ... of two atoms of hydrogen, one of sulphur, and four of oxygen.

Page 75 - ... 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 39 - 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 362 - ... it is only within the last year or two that they have become a real commercial proposition.

Page 39 - British system of units, a unit of force is the force which would give a mass of 1 lb. an acceleration of 1 foot per second every second. In the CGS system the unit is that force which would give a mass of 1 gram an acceleration of 1 cm. per second every second. This is called a " dyne." A weight of 1 gram exerts a force of 981 dynes, ie gravity would give a mass of 1 gram in falling an acceleration of 981 cms. per second every second. Work. — Work is always done or energy is expended...

Page 116 - Fig. 47 shows how the successive current amplitudes in an oscillatory discharge diminish in size until eventually the discharge ceases. The oscillations are said to be damped and this is caused by the energy losses in resistance, radiation, and transfer. It is very important to know the extent of this damping of the oscillations in a wireless circuit, and it is measured by taking the logarithm of the ratio of successive current amplitudes in the same direction. This is called the " Logarithmic Decrement,"...

Page 14 - Ta 181-0 Gold Au 197-2 Tellurium Te 127-5 Helium He 3-99 Terbium Tb 159-2 Hydrogen H 1-008 Thallium Tl 204-0 Indium In 114-8 Thorium Th 232-0 Iodine I 126-92 Thulium Tm 1685 Iridium Ir 193-1 Tin Sn 119-0 Iron Fe...

Page 89 - ... cycle and the number of cycles per second is called the. frequency of the machine or circuit in which its current flows.