Homework 8 Answers

6.1

(a) i = 0 for t < 0, i = 50t for 0 ≤ t ≤ 5 ms, i = 0.5 - 50t for 5 ≤ t ≤ 10 ms, i = 0 for t > 10 ms

(b) v = 0 for t < 0, v = 1 V for 0 ≤ t ≤ 5 ms, v = -1 V for 5 ≤ t ≤ 10 ms, v = 0 for t > 10 ms

p = 0 for t < 0, p = 50t W for 0 ≤ t ≤ 5 ms, p = 50t - 0.5 W for 5 ≤ t ≤ 10 ms, p = 0 for t > 10 ms

w = 0 for t < 0, w = 25t² J for 0 ≤ t ≤ 5 ms, w = 25t² - 0.5t + 0.0025 J for 5 ≤ t ≤ 10 ms, w = 0 for t > 10 ms

6.5  

(a) i = -10t² A for 0 ≤ t ≤ 1 s, i = 10t² - 40t + 20 A for 1 ≤ t ≤ 3 s, i = 20t - 70 A for 3 ≤ t ≤ 5 s, i = -10t² + 120t - 320 A for 5 ≤ t ≤ 6 s

(b) 40 A

6.16

(a) i = 0

(b) i = (32cos500t + 36sin500t)e^-1000t mA

(c) no

(d) yes, from 0 to 32 mA

(e) v_infinity = 40 V, w = 640 mJ

6.20) 8 H

6.26) 2 mF

7.1)

(a) i₁(0^-) = 5 mA, i₂(0^-) = 15 mA

(b) i₁(0⁺) = 5 mA, i₂(0⁺) = -5 mA

(c) i₁(t) = 5e^-20,000t mA

(d) i₂(t) = -5e^-20,000t mA

7.22)

(a) v(t) = 59.4e^-1000t V, i₀(t) = 9.9e^-1000t mA

(b) 42.14 %

7.48)

(a) v₀(t) = (60 - 60e^-100t) V

(b) i₀(t) = (1 - 0.6e^-100t) mA

(c) i₁(t) = (1 + 2.4e^-100t) mA

(d) i₂(t) = (4 - 2.4e^-100t) mA

(e) 3.4 mA