FUNDAMENTALS OF ELECTRICAL ENGINEERING — Major (End Semester) 2021 question paper
MMMUT Electrical Engineering previous year question paper for FUNDAMENTALS OF ELECTRICAL ENGINEERING (BEE-151), semester 1, Major (End Semester) 2021. All 24 questions are listed below, each with a written answer on Nexsus.
Paper details
Subject: FUNDAMENTALS OF ELECTRICAL ENGINEERING (BEE-151)
Branch: Electrical Engineering
Semester: 1
Exam: Major (End Semester) 2021
Questions: 24
Questions asked in FUNDAMENTALS OF ELECTRICAL ENGINEERING Major (End Semester) 2021
Q1(a). A 12V dc source with internal resistance of 2 ohm is feeding maximum power to the load; find the maximum power delivered to the load. [2 marks]
Q1(b). Find current in 2 ohm resistance using Thevenin's theorem as shown in figure 1. [2 marks]
Q1(c). Find the form factor of a half-wave sine wave. [2 marks]
Q1(d). An alternating voltage is given by v = 100 sin 100t, find: amplitude, frequency and angular velocity. [2 marks]
Q1(e). Explain the following terms: MMF, Reluctance, Relative permeability and hysteresis. [2 marks]
Q1(f). Derive the expression for the emf equation of a DC machine. [2 marks]
Q2(a). Find the current in 1 ohm resistance using nodal analysis as shown in figure.2. [5 marks]
Q2(b). Find the current in all the resistances of the circuit as shown in figure.3 using superposition theorem. [5 marks]
Q2(c). Find current in branch BD using Mesh analysis as shown in fig.4. [5 marks]
Q3(a). Define the RMS value of alternating current waveform. A triangular wave AC wave has a time period of 10 msec and peak value of current of 50 mA. Find (i) Frequency (ii) RMS value (iii) Average value and (iv) Form factor. [5 marks]
Q3(b). A series RLC circuit has R = 10 ohm, L = 0.1 H and C = 8 microF. Determine (i) resonant frequency (ii) Q- factor of the circuit at resonance (iii) half power frequency. [5 marks]
Q3(c). A balanced three phase, star connected load of 180 kW is taking a leading current of 300 A when connected to three phase, 440 V, 50 Hz supply. Find the values and nature of load components and also power factor of the load. [5 marks]
Q4(a). Explain the basic difference between electric and magnetic circuit. What is magnetic hysteresis and find that the hysteresis loss is given by the area of the hysteresis loop. [5 marks]
Q4(b). An iron ring of mean diameter 22 cm and cross section 10 cm^2 has an air gap 1 mm wide. The ring is wound uniformly with 200 turns of wire. The permeability of iron is 1000. A flux of 0.16 mWb is required in the air gap. Find the current passing through the wire. [5 marks]
Q4(c). In a transformer explain why windings are sub-divided. Describe with relevant circuit diagram, the open circuit and short circuit test of a transformer. [5 marks]
Q5(a). A 500 V, 1000 rpm DC machine with 4 poles has flux per pole of 20 mWb. The current in each armature conductor is 10 A. Neglecting all the losses in the machine, find; (i) total no. of conductors (ii) total armature current and (iii) armature torque when machine is lap connected. [5 marks]
Q5(b). Explain the working principle of operation of single phase induction motor. Why it is not self- starting. Describe its method of starting. [5 marks]
Q5(c). Draw and explain the working principle of three phase induction motor. Also draw its torque-slip characteristics for variable rotor resistances. [5 marks]