{"product_id":"geophysics-iii-geophysik-iii-part-iii-teil-iii-softcover-reprint-of-the-original-1st-1971","title":"Geophysics III\/Geophysik III","description":"\u003cp\u003e\"Geophysics III\/Geophysik III\" by Karl Rawer is a physics book focused on Astronomical Data. Best for students, educators, and scientifically curious readers.\u003c\/p\u003e\n\u003cp\u003eSect. 14. 297 for such slow variations the effect described under 2. above will be by far the most predominant. In fact, the equipment provides a record of the time derivative of the element in question. 6) Records of the time derivatives of magnetic elements can, however, be obtained in a more direct way by recording directly the electromotive force (e. m. f. ) induced in suitably disposed coils by the variations of the geomagnetic field 10, 11. When a coil with the total winding area F is placed with its axis in the direction of a geomagnetic force component the variation of magnetic induction B with time will produce an electromotive force 1 dB 1 dH e=- coveu,uuFdT=- 'oV~,uQf1oFdT (i). )) . !. . =_to-13~ d(B\/y) (1). )a) v em! d(tjs) in the coil. The e. mJ. may be amplified and recorded by means of an oscillograph or on a tape recorder. but more often the coil is used in connection with an ordinary galvanometer and the scale value of, for instance the dl1\/dt record, will then - in the same way as the scale value of the magnet variometer treated in Subsect. IX - be dependent on the damping factor IX and on TO\/T, where To and T are the oscillation periods for the undamped galvanometer and for the magnetic pulsation respectively. The amplitude recorded will be proportional to the amplification factor I, obtained from Eq. (1).\u003c\/p\u003e","brand":"Springer","offers":[{"title":"Default Title","offer_id":46420238336199,"sku":"1-99-526-000258","price":109.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0736\/9575\/6487\/files\/9783642806414.jpg?v=1776329480","url":"https:\/\/snowflakeskies.com\/products\/geophysics-iii-geophysik-iii-part-iii-teil-iii-softcover-reprint-of-the-original-1st-1971","provider":"Snowflake Skies","version":"1.0","type":"link"}