Question

a) What resistance R (in Ω) must be connected in series with a 250 mH inductor and a 2.0 µF capacitor if the resulting RLC oscillating circuit is to decay to 50% of its initial value of charge in 20 cycles?

___________________________Ω

b) What is the resistance (in Ω) if the charge is to decay to 0.10% of its initial value in 20 cycles?

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Answer 1

- w't ++) q = Q e ² ? Q e [ cool wtto) assuming , / دی - Rt/22 هغه (هاف) نوع و ماده ه a = initial charge at tro sec د لا هوية .. se zu . lol Imax Jena 2L Now ; . we heed t - 20 T time for 20 cycles = 20 (21 cc) : t = 20 x 21 V 250 x103 x 2 x 10-6 t = 0.039 & Imax = 0.500 eqa ou becomes In 10.50) 3 - Rt 2L . t R = -2L enco.ro) 1.25 kioentoso) TAR= 3.gor/ - 2* 250

b) 9 max = 0.001 Q from egno ln (0.001) . - Rt .R. -24 2040.001) - 2x 250 x 10-3 0,089 .. R = 38.92