<span>Charge of the glass bead Q = 8.0 x 10^-9 C
Distance d = 2.0 cm = 0.02 m
Coulombs constant K = 8.99 x 10^9 Nm^2/C^2
Electric Field E = k x Q / d^2 = 8.99 x 10^9 x 8.0 x 10^-9 / (0.02)^2
E = 71.92 / 0.0004 = 17.98 x 10^4
The electric field is 1.8 x 10^5 N/C</span>
As we know that in transformers we have

here we know that



now from above equation we will have



The force that opposes motion to moving parts is F<span>riction</span><span>
Hope this helped!
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