Electrical Circuits

Daffodil International University Faculty of Science & Information Technology Department of Computer Science & Engineering Midterm Examination, Fall 2026 Course Code: CSE121 Course Title: Electrical Circuits Level: 1 Term: 3 Batch: 71 Time: 1:30 Hrs Full Marks: 25 Answer all the following Three questions [All portions of each question must be answered sequentially] Q1. a. Define an electrical circuit with a simple diagram. [5x1 = 5 | CO1] b. State DC and AC current and show them in the time domain. c. Define a dependent current source with a symbol. d. Define a loop and a mesh in an electrical circuit. e. Write a short note on Thevenin's Theorem. Q2. a. Solve for the total current of the following circuit, if a voltage source of 22.4 V is applied between the points a and b : [2x5 = 10 | CO2] [Figure: Bridge-T resistor circuit connected across terminals a and b with resistors labeled 10 Ω, 1 Ω, 1 Ω, 6 Ω, 12 Ω, 3 Ω, 4 Ω, and 5 Ω] b. Apply mesh analysis to determine the current i_o and the voltage v_ab in the following circuit : [Figure: Circuit with two 80 V voltage sources, three 20 Ω resistors, and three 30 Ω resistors arranged in multiple loops, showing current i_o and terminal voltage v_ab] Q3. a. Analyze the following circuit using the superposition theorem by determining the contribution of each independent source separately and hence finding the output voltage, v : [2x5 = 10 | CO3] [Figure: Circuit diagram with a 6 V independent voltage source, 8 Ω resistor, 4 Ω resistor with voltage v, and a 3 A independent current source] b. Analyze the circuit using Norton's theorem by obtaining the Norton equivalent circuit at terminals a and b in the following circuit : [Figure: Circuit diagram containing a 2 A independent current source, a 4 Ω resistor in series with a 12 V voltage source, two 8 Ω resistors, a 5 Ω resistor, and terminals a and b]