Question

Q1): Part 2 [9 marks] The switch in Fig. 2 has been closed for a long time. At t = 0, the switch is opened. a) Calculate iz (0) [2 marks] b) Find iz(0) [2 marks] c) Find I [2 marks] d) Find iz(t) [1 marks] e) Find vu(t) [2 marks] 302 _ 4.22 MW 12 24V(+) en} ww Www 12V + Fig. 2 RL circuit with DC input.

Answer 1

y given ir SIR 354 Son fr 240 120 « Cot] =? as induntur does not allow endten change of current so I, CO) = IL 607 = I4 (6+7 at tao (steady state circuit is

120 ' 6+G apply Noday analu. analysis at v V-24 V + -0 V -12 V- o =0 4+3 vrt+1+47 = 24 +12 106011 V = 20 V= 12.49 volt 67 Now I fot] = lyx oc po 5 lety now I u = ve ay = 12:49 (14 = 107842 Amp Iz Cot] = 0.892) nup

Il lnd] =? at t o the circuit apply Nodal analysis at u V= 12 + = + = = 0 avg+=++] = La v=4.5 volt i [_(a)= vo z ve [[ 2007 = 0.75 Amp 5D = ? الحي/

Req=? 4r 32 - Ref Ear redundant Req = 6+ 6/1 (+y) = 6+ 645 Req = 8.7212 21 :: Parent P= 0.5729 sec d) Iz(t) = ? IĮ (t) is given by I(t) = Iz () + (7 607)- Ep (my]être Iltti = 0.75 +(0.8921–0.757 ēt/0.5729 = Il(t) = 0.75+0.1427 7 1745+ Am

VLH = ? Y(t)= L dillu) dt = y(t) = 5 d (0.75 +0-1427ē 161454] «lt) =s (0+ 0-142) (-1-7467 ēlaust V(t) =-1.24 ē 17457 volt