Physics question help!! O ao points Previous Answors SerPSE 28 Po39 w A 2.00 nF
ID: 1325805 • Letter: P
Question
Physics question help!! O ao points Previous Answors SerPSE 28 Po39 w A 2.00 nF capacitor with an initial charge of 5.41 wc is discharged through a 1.B5-kn resistor (a) Calculate the current in the resistor g oo ps after the resistor is connected across the terminals of the capacitor. (Let the positive direction of the current be define such that s 0.) How is the instantaneous current related to the poteetial difference across the capacitor? MA b) what charge remains on the capacitor after 8.00 vs? (c) What is the (magnitude of the) maximum current in the resistor? Need Help? l
Explanation / Answer
a)
C = Q/V so V = Q/C
Initial V = (5.1E-6) / (2.00E-9) = 2550V
Time constant = RC = 1300 x 2.00E-9 = 2.60E-6 s (=2.60 us)
Initial current = V/R = 2550 / 1300 = 1.96A
Current afer 9.00us = 1.96e^(-9.00E-6 / 2.60E-6) = 0.0615 A
b) Q = 5.10E-6 x e^(-8.00E-6 / 2.60E-6) = 2.35E-7 C = 0.235 uC
c) The max current = initial current =1.96A