# Essay about ECT122 Wk7 Assignment

736 WordsJan 14, 20153 Pages
Week 7 Homework Assignment Chapter 7 Circuit Analysis Techniques 15. Derive the Thevenin equivalent of the circuit shown in Figure 7.47a. Req= (R1+R2)//(R3+R4)= 5.2k//1.5k= 1164 x 10^3= 1.2kΩ Rth= Req+R5= 1.2kΩ+1kΩ= 2200 x 10^3= 2.2kΩ Vth= Vs= 9V 16. Derive the Thevenin equivalent of the circuit shown in Figure 7.47b. Req= R1+R2= 22+33= 55Ω Vth= Vs x R3/Req+R3+R4= 12V x 120Ω/55+120+51 = 6.37V Rth= (R1+R2)//(R3+R4)= (22+33)//(120Ω+51Ω)= 41.6Ω 17. Derive the Thevenin equivalent of the circuit shown in Figure 7.48a. Req= R1//R2 = 1.2k // 1.8k = 720Ω Vth= Vs x R3/ Req+3 = 10V x 1kΩ/720Ω+1kΩ = 5.81V Rth= Req//R3= 720Ω//1kΩ = 418.6Ω = 418.6 =419Ω 18. Derive the Thevenin equivalent of the circuit shown in Figure 7.48b. Vth= Vs x R3/R2+R3= 6V…show more content…
Vrms= 0.707Vpk= 0.707 x 100V= 70.7V Ipk= Vpk/RL= 100V/12Ω= 8.33A Irms= 0.707Ipk= 0.707 x 8.33A= 5.88A 27. Complete the following table. Frequency(f) Period(T) Instantaneous Time(t) Phase(0) __100Hz___ 10ms 2ms _72°___ 120kHz __8.33µs__ ____1.38µs____ 60° _22Hz___ 45ms ______12.5ms______ 100° __25Hz__ __40ms_____ 10ms 90° a.) f=1/T= 1/10ms= 100Hz 0= (360°) x t/T= (360°) x 2ms/10ms= 72° b.) T= 1/f= 1/120kHz= 0.00000833 x 10^-6= 8.33µs t= T x 0/360°= 8.33µs x 60°/360°= 0.00000138 x 10^-6= 1.38µs c.) f= 1/T= 1/45ms= 22Hz t= Tx0/360°= 45ms x 100°/360°= 0.0125 x 10^-3= 12.5ms d.) f=1/T= 1/40ms= 25Hz T= 40ms, I figured this by guessing cause I could not find any information on how to calculate. So I used the equation for t and plugged in different numbers until I got the 10ms that was already given in the table. t= T x 0/360= 40ms x 90/360= 0.01 x 10^-3= 10ms 28. Complete the following table. Frequency(f) Period(T) Instantaneous Time(t) Phase(0) __10kHz__ 100µS 40µs _144°__ 2MHz _500ns___ ___278ns_________ 200° __20Hz____ 50ms _____42ms______ 300° __133Hz____ __7.5ms____ 1.25ms 60° a.) f=