In a defibrillator, a charged capacitor is connected to paddles that make electr
ID: 1633175 • Letter: I
Question
In a defibrillator, a charged capacitor is connected to paddles that make electrical contact with the patient's skin. If gel is applied to the patient's chest to make a good connection between the paddles and the skin, the effective resistance through which the capacitor discharges is 57 Ohm. (a) To what voltage must the capacitor be charged to generate a maximum current of 30 A? (b) If the current 1.00 ms later is 13 A, what is the capacitance? Round your final answers to one decimal place. (a) Delta V_max, C = 1710 V. (b) C = 1.0| mu F.Explanation / Answer
(a)
maximum voltage is
Vmax = I max R = 30 ( 57) = 1710 V
(b)
The growth of current in RC circuit is
I = Imax ( 1- e^- t/RC)
13= 30 ( 1- e^-1.0* 10^-3/57 C)
e^-1.0* 10^-3/57 C=0.566
-1.0* 10^-3/57 C= ln (0.566)
C=30.88 uF