University of Mumbai first-year engineering Semester I Basic Electrical & Electronics Engineering paper, December 2024, NEP 2020 scheme, with step-by-step solutions written with AI help and checked.
Mumbai University FE Sem 1 Basic Electrical & Electronics Engineering (ESC102) Question Paper December 2024
Written semester papers (NEP 2020 scheme): 60 marks and 2 hours for most first-year courses. Question 1 is compulsory, then any three of questions 2 to 6.
Sections
| Q.1 Attempt all (compulsory) | 5 questions | |
| Q.2 | 2 questions | |
| Q.3 | 2 questions | |
| Q.4 | 3 questions | |
| Q.5 | 3 questions | |
| Q.6 | 3 questions |
Chapters covered
Instructions
Solve on paper with a timer, then check against the solutions.
Q.1 Attempt all (compulsory)
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Q.1 (a) Write formulas for Delta to Star and Star to Delta transformation.
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Q.1 (b) An alternating current of frequency 50 Hz has a maximum value of 12 A. Find (i) Equation for instantaneous value of current and (ii) Time taken to reach 9.6 A for the first time.
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Q.1 (c) What is the efficiency of transformer?
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Q.1 (d) State the function of each constructional part of a DC motor.
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Q.1 (e) Write applications of LED.
Q.2
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Q.2 (a) Using Superposition theorem, find voltage across 4 Ω resistor.
[Circuit: a common bottom wire (reference). Left vertical branch: a 10 A current source between the bottom wire and the top-left wire, arrow pointing upward (current delivered into the top node). The top-left wire runs right to node X (marked with a dot). From X a 4 Ω resistor goes down to the bottom wire. From X a 1 Ω resistor in the top wire goes right to node Y. From Y a 25 V battery goes down to the bottom wire (longer plate, +, at the top toward Y). From Y the top wire continues right through a 15 V battery (longer plate, +, on the right side) to the top-right corner, and from there a 3 Ω resistor goes down to the bottom wire.]
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Q.2 (b) Explain the working principle of three phase induction motor.
Q.3
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Q.3 (a) A coil consumes 1 KW power from 50 Hz single phase ac supply and volt-ampere input is 2 KVA. If value of resistance of coil is 10 Ω then find the following parameters with respect to a coil. (i) Value of inductance, (ii) Phase angle, (iii) Power factor, (iv) Impedance, (v) Voltage and Current equations, (vi) KVAR
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Q.3 (b) Draw and explain the V-I characteristics of a Zener diode
Q.4
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Q.4 (a) State and prove the Maximum power transfer theorem. Derive the formula of Maximum power delivered.
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Q.4 (b) Explain the application of BJT as an amplifier.
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Q.4 (c) Three similar coils each having a resistance of 5 Ω and an inductance of 0.02 H are connected in star to a 440 V, 50 Hz, 3-phase supply. Calculate (i) line current and (ii) active and reactive power
Q.5
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Q.5 (a) Explain the working principle and transformation ratio of a single-phase transformer.
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Q.5 (b) Write short note on any one: (i) Single phase induction motor (ii) BLDC motor.
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Q.5 (c) Two impedances of 12 + j16 Ω and 10 − j20 Ω are connected in parallel across 230 V, 50 Hz, single phase ac supply. Find admittance, current and power factor of each branch.
Q.6
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Q.6 (a) Find current flowing through 1 Ω resistance by Node analysis.
[Circuit: a common bottom wire (reference). Left vertical branch: a 4 V battery from the bottom wire up to the left node L (longer plate, +, at the top). From L the left vertical wire continues up to a top wire. The top wire contains a 1 A current source with arrow pointing right (from the left side toward the right side) and ends at the top-right corner, which joins the right vertical wire at node R. In the middle row, a 2 Ω resistor runs from L to the middle node M, and a 3 Ω resistor runs from M to node R. A 1 Ω resistor goes from M down to the bottom wire. Right vertical branch: a 3 A current source between the bottom wire and node R, arrow pointing upward (into R).]
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Q.6 (b) State the necessary condition for resonance in a series circuit. Compare series and parallel resonance.
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Q.6 (c) Write a short note on FET.