Basic Electrical Engineering (BEE) SPPU Endsem Question Paper Dec 2025

Questions

1. Q1

   1. a)

      Find current through 8 Ohm resistance using KVL.

      [6]
   2. b)

      Explain typical power system with neat block diagram. Mention voltage levels of every section.

      [6]
   OR

2. Q2

   1. a)

      Find current through 8 Ohm resistance using Super position theorem.

      Also asked:May 2025

      [6]
   2. b)

      Derive the formulae for conversion of delta to equivalent star connected network. Draw neat circuit diagram. [8] SPPU QUESTION PAPER www.mysppu.in Page 1 MySPPU · Basic Electrical Engineering Page 1 of 3

3. Q3

   1. a)

      A steel ring of 175 cm mean diameter has a cross-sectional area of 250 mm2. Flux developed in the ring is 500 uwb when 3500 turns coil carries certain current. Assuming u, of steel to be 1250. Find i) mmf required ii) reluctance iii) current

      [6]
   2. b)

      Define magnetic circuit. State any 04 similarities and any 02 dissimilarities with electrical circuit.

      [8]
   OR

4. Q4

   1. a)

      a) Define reluctance. Write formula and its unit. State the formula for reluctance magnetic circuit i) having only iron path ii) having iron path & one air gap.

      [6]
   2. b)

      With usual notation derive the formula for self-induced emf. Enlist the factors affecting self-inductance.

5. Q5

   1. a)

      This part has equations that don’t show as text. Open the PDF to read it.

      [6]
   2. b)

      Define average value of an alternating quantity. Obtain an expression for average value in terms of maximum value.

      [6]
   OR

6. Q6

   1. a)

      An AC voltage of 𝑣 = 250 𝑠𝑖𝑛 (314.16𝑡) applied to a pure capacitance of 125 μF. i) Write equation for current ii) Draw phasor diagram iii) Average power consumed.

      [6]
   2. b)

      This part has equations that don’t show as text. Open the PDF to read it.

      [8]

7. Q7

   1. a)

      A coil having resistance of 7 and an inductance of 31.8 mH is connected to single phase 230V 50 Hz AC supply. Calculate i) Impedance ii) Current through circuit iii) Power factor iv) Power consumed v) Voltage dross resistance and inductor

      [6]
   2. b)

      What is series resonance? Derive the expression for resonance frequency. Draw phasor diagram for resonance condition. OR SPPU QUESTION PAPER www.mysppu.in Page 2 MySPPU · Basic Electrical Engineering Page 2 of 3

      [6]

8. Q8

   1. a)

      Each phase of star connected load has an impedance 25 + 𝑗40 connected across 3 phase 415 V 50 Hz supply. Find i) Phase and line current ii) All powers

      [6]
   2. b)

      Derive formula for relation between phase voltage and line voltage in delta connected resistive load. State formulae for all powers in terms of only line parameters.

      [6]

9. Q9

   1. a)

      80 KVA 1000/250 V 50 Hz, 800 watt and full load copper loss of 1200 watt. Estimate i) Efficiency at full load 0.8 power factor ii) Efficiency at half load unity power factor

      [6]
   2. b)

      Compare between core and shell type of single-phase transformers [8]

      [6]
   OR

10. Q10

    1. a)

       Explain the working principle of 3 phase squirrel cage induction motor. State any two applications.

       [6]
    2. b)

       This part has equations that don’t show as text. Open the PDF to read it.

       [6]