Practical Electricity and Magnetism |
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absolute measure adjusted altered ampères angle apparatus balance ballistic galvanometer battery brass bridge wire C.G.S. units calculated calibration capacity centimetre centre charged circuit Clark cell coefficient of self-induction coil condenser connected constant copper curve CuSO Daniell cell deflection determined diameter dielectric earth inductor ebonite effect electrometer employed ends experiment fall of potential farads galvano galvanometer needle glass guard-ring heat Ibid induction inductor instrument insulated iron J. J. Thomson length liquid loge manganin means mercurous sulphate mercury metal meter method of measuring microfarads number of turns obtained ohms oscillator Phil placed plate position potential difference potentiometer quadrants quantity of electricity R₁ ratio readings ring rotated scale scale-divisions self-induction shown in Fig solenoid solution specific resistance spot of light standard cell steady currents sulphate swing taken terminals tube volt voltameter Wheatstone bridge zero zinc zinc sulphate
Popular passages
Page 115 - As a unit of resistance, the international ohm, which is based upon the ohm equal to 10" units of resistance of the CGS system of electromagnetic units, and is represented by the resistance offered to an unvarying electric current by a column of mercury at the temperature of melting ice, 14.4521 grams in mass, of a constant cross-sectional area and of the length of 106.3 centimetres.
Page 177 - Prepare a neutral saturated solution of pure (" pure recrystallized ") zinc sulphate by mixing in a flask distilled water with nearly twice its weight of crystals of pure zinc sulphate, and adding zinc oxide in the proportion of about 2 per cent by weight of the zinc sulphate crystals to neutralize any free acid. The crystals should be dissolved with the aid of gentle heat, but the temperature to which the solution is raised should not exceed 30° C.
Page 176 - The volt, which has the value 10s, in terms of the centimetre, the gramme, and the second of time, being the electrical pressure that, if steadily applied to a conductor whose resistance is one ohm, will produce a current of one ampere, and which is represented by 0'6974 ({•£££) of the electrical pressure at a temperature of 15° C.
Page 177 - C. Keep the paste for an hour at this temperature, agitating it from time to time, then allow it to cool ; continue to shake it occasionally while it is cooling. Crystals of zinc sulphate should then be distinctly visible, and should be distributed throughout the mass.
Page 154 - Care must be taken that the clock used is keeping correct time during this interval. The solution is now removed from the bowl and the deposit is washed with distilled water and left to soak for at least six hours. It is then...
Page 154 - C. After cooling in a desiccator it is weighed again. The gain in weight gives the silver deposited. To find the current in amperes, this...
Page 154 - The anode is then immersed in the solution so as to be well covered by it, and supported in that position ; the connections to the rest of the circuit are made.
Page 178 - The ends of the wire project from the ends of the tube ; one end forms the terminal, the other end and a portion of the glass tube dip into the mercury. Clean the glass tube and platinum wire carefully, then heat the exposed end of the platinum red hot and insert it in the mercury in the test-tube, taking care that the whole of the exposed platinum is covered.
Page 154 - The liquid should consist of a neutral solution of pure silver nitrate, containing about 1 5 parts by weight of the nitrate to 85 parts of water. " The resistance of the voltameter changes somewhat as the current passes. To prevent these changes having too great an effect on the current, some resistance besides that of the voltameter should be inserted in the circuit.
Page 176 - CELL. Definition of the Cell. The cell consists of zinc or an amalgam of zinc with mercury and of mercury in a neutral saturated solution of zinc sulphate and mercurous sulphate in water, prepared with mercurous sulphate in excess.