Please do a-e. Thanks (17%) Problem 6: A capacitor of capacitance C 3.5 F is ini
ID: 1782350 • Letter: P
Question
Please do a-e. Thanks
(17%) Problem 6: A capacitor of capacitance C 3.5 F is initially uncharged. It is connected in series with a switch of negligible resistance, a resistor of resistance R = 13 kQ, and a battery which provides a potential difference of 175 V ©theexpertta.com > 20% Part (a) Immediately after the switch is closed, what is the voltage drop rc, in volts, across the capacitor? Grade Summa Deductions Potential ry 0% 100% 7 8 9 sin0 cotan0asin acos0 atan0 acotan sinhO cosh0 tanh cotanh0 cosO Submissions Attempts remaining: 20 (0%per attempt) detailed view Degrees Radians NO Submit Hint I give up! Hints: 0% deduction per hint. Hints remaining: Feedback: 0% deduction per feedback. 20% Part (b) Immediately after the switch is closed, what is the voltage drop VR, in volts, across the resistor? 20% Part (c) Immediately after the switch is closed, what is the current I in amperes, through the resistor? 20% Part (d) Find an expression for the time t12 after the switch is closed when the current in the resistor equals half its maximum value - 20% Part (e) What is the charge Q, in microcoulombs, on the capacitor when the current in the resistor equals one half its maximum valueExplanation / Answer
a)
By KVL
VB = VR + VC
VB = IR + Q/C
Qt =CVB[1-e-t/RC]
At t= 0s, Q= 0 C
Hence,
VC = 0 V
b)
VR = VB = 175 V
c)
VR = IR
I= VR /R = 175/13000 = 0.0135 A
d)
It= I0*e-t/RC
It=VB /R*e-t/RC
When It=0.5I0
0.5I0 = I0*e-t/RC
0.5 = e-t/RC
ln0.5 = -t/RC
t=(1/1.4427)*RC
t1/2 = t = (1/1.4427)*(13000*3.5*10^-6) = 31.54ms
e)
Qt =CVB[1-e-t/RC]
Qt = (3.5*10^-6*175)*[1-e-0.031.54/(1300*3.5*10^-6)] = 0.612mC