Aptitude Test Problems in Physics Science for Everyone by S Krotov ( PDFDrive.com )

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  1. Electricity and Magnetism (^77)
    3.12•. The thickness of a flat sheet of a met-
    al foil is d, and its area is S. A charge q
    is located at a distance (^1) from the centre of
    the sheet such that d< VE <1.
    Determine the force F with which the
    sheet is attracted to the charge q, assuming
    that the straight line connecting the charge
    to the centre of the sheet is perpendicular
    to the surface of the sheet.
    A
    2\N C 2
    8 z
    Fig. 78 Fig. 79
    3.13. Where must a current source be con-
    nected to the circuit shown in Fig. 79 in
    order to charge all the six capacitors having
    equal capacitances?
    3.14. A parallel-plate capacitor is filled by
    a dielectric whose permittivity varies with
    the applied voltage according to the law
    e = all, where a = 1 V-1. The same (but
    containing no dielectric) capacitor charged
    to a voltage U 0 = 1.56 V is connected in
    parallel to the first "nonlinear" uncharged
    capacitor.
    Determine the final voltage U across the
    capacitors.

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