rl_rc_problem1

rl_rc_problem1 - Sample problems Topic RC and RL circuits...

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

Sample problems Topic: RC and RL circuits Statement of problem In the circuit shown in the figure, the switch has been in position a for a long time. At t=0, it moves instantaneously from a to b. (a) Find 0 () vt for 0 t . (b) What is the total energy delivered to the 1 k Ω resistor? (c) How many time constants does it take to deliver 95% of the energy found in (b)? Solution (a) At t=0, the steady state of the circuit is 2.5 mA 16 k Ω 4 k Ω (0) L i The steady current (0) L i is also the initial current for t>0. By KCL, it is 16 (0) 2.5 2 16 4 L k im A m A kk Ω =− × Ω+ Ω At t=0, the switch turns to position b, so the circuit is like 120 mH 0 v + 1 k Ω 60 mH (0) L i The PARALLEL inductance in this circuit is 120 60 120 / /60 40 120 60 mH mH mH mH mH mH mH × == + Therefore the time constant for this RL circuit is

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

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 10/30/2011 for the course EE 215 taught by Professor Unknown during the Spring '05 term at University of Washington.

Page1 / 2

rl_rc_problem1 - Sample problems Topic RC and RL circuits...

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

View Full Document
Ask a homework question - tutors are online