Course
EEE102
Name Surname
Exam
Quiz1
Student ID
Date
13.03.2025
Signature
Date
Q1
Duration
20 min.
LO
Grade
Notes: Closed books, no smart devices.
Q1[50p] The charge through an element is given as,
𝑞(𝑡) = 8 cos 100𝜋𝑡 + 5 sin 40𝜋𝑡 𝑚C
Determine the current through this element at 𝑡 = 0.25 𝑠.
Solution:
𝑖(𝑡) =
𝑑𝑞
= −800𝜋 sin 100𝜋𝑡 + 200𝜋 cos 40𝜋 𝑡 𝑚A
𝑑𝑡
𝑖(0.25) = −800𝜋 sin 100𝜋 × 0.25 + 200𝜋 cos 40𝜋 × 0.25
= −800𝜋 sin 100𝜋 × 0.25 + 200𝜋 cos 40𝜋 × 0.25
= −800𝜋 sin 25𝜋 + 200𝜋 cos 10𝜋
= −800𝜋 × 0 + 200𝜋 × 1 = 628.3 mA
= 200𝜋 = 628.3 mA
Q2
Q3
Q4
Total
Q2[50p] In the following circuit, determine the power for each element and state whether it absorbs or supplies
the power.
Solution:
𝑝1 = 30 × (−5) = −150 W → Supplying
𝑝2 = 𝑉0 × 5 → 𝑡𝑜 𝑏𝑒 𝑑𝑒𝑡𝑒𝑟𝑚𝑖𝑛𝑒𝑑
𝑝3 = 38 × 2 = 76 W → Absorbing
𝑝4 = 28 × 2 = 56 W → Absorbing
𝑝5 = 28 × 1 = 28 W → Absorbing
𝑝6 = 10 × 3 = 30 W → Absorbing
Using power conservation principle, we get
𝑝1 + 𝑝2 + 𝑝3 + 𝑝5 + 𝑝6 = 0
−150 + 𝑝2 + 76 + 56 + 28 + 30 = 0
⟹ −150 + 190 + 𝑝2 = 0
⟹ 𝑝2 = −40 W Supplying