17_Chapter 20 HomeworkCH20 Induced Voltages and Inductance

17_Chapter 20 HomeworkCH20 Induced Voltages and Inductance...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
Induced Voltages and Inductance 191 20.44 The current in the RL circuit at time t is ( 1 t Ie R ) τ ε =− . The potential difference across the resistor is ( ) 1 t R VR I e ∆== − , and from Kirchhoff’s loop rule, the potential difference across the inductor is ( ) 11 tt LR VV ee εε −−  ∆=− ∆= =  (a) At 0 t = , ( ) () 0 1 R Ve 0 − = −= (b) At t = , ( ) ( ) 1 1 6.0 V 1 0.368 3.8 V R − = = (c) At 0 t = , 0 6.0 V L == (d) At t = , 1 6.0 V 0.368 2.2 V L = = 20.45 From ( ) max 1 t e II , max 1 t I e I If max 0.900 I I = at , then 3.00 s t = 3.00 s e 0.100 = or 3.00 s 1.30 s ln 0.100 Since the time constant of an RL circuit is = , the resistance is 2.50 H 1.9 1.30 s = 2
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

This document was uploaded on 10/20/2011.

Ask a homework question - tutors are online