DQ7C_solution - Discussion Question 7C P212, Week 7 RC...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Discussion Question 7C P212, Week 7 RC Circuits The circuit shown initially has the capacitor uncharged, and the switch open. At time t = 0, the switch is thrown. Write all answers in terms of E , R, and C as needed. (a) At 0 + = t , immediately after the switch is thrown what is the current (0 ) + I ? + cap Consider applying KVL around the loop that includes the battery and the capacitor. - 0. At t=0 Q =0 0 0 (0 ) / + Δ− = Δ= = = cap cap VI R V I R I R E E ±E (b) After a very long time, what is the current I ? 12 When the capacitor is fully charged it acts like an open circuit. Hence all current flows through . The current is then I = / 2 . + RR R (c) After a very long time, what is the charge on the capacitor Q ? Consider the KVL that just consists of the capacitor and the one resistor. 0 -/ 0 0 22 ∞∞ −Δ = →= = = cap IR V IRQ C RQ C Q C R EE (d) Assume ( ) (1 exp( Qt Q t β =− ) ) gives the charge on the capacitor as a function of time. Use () 0 0 + + ⎡⎤ = ⎢⎥ ⎣⎦ dQ I dt and your answers to (a) and (c) to compute .
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 2

DQ7C_solution - Discussion Question 7C P212, Week 7 RC...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online