B.TECH - Semester 8 electrical drives and control Question Paper 2021 (feb)
Practice authentic previous year university questions for better exam preparation.
Sample Questions
- Explain the principle of. operation of DC generator
- Explain why dc series motor is used in starting of high inertia loads.
- Explain why single phase induction motor is not self starting.
- Explain the principle of operation of power MOSFET.
- Explain are the main difference between MOSFET and BJT.
- Write down the expression of average output voltage for half wave rectifier connected to resistive load.
- Explain the term holding current latching current in SCR.
- Explain the significance of freewheeling diode.
- Explain Multipulse modulation technique.
- List the merits and demerits of online and offline ups. Answer any one full questions from each Module. Each question carries 20 marks.
- (a) Explain the working principle of a single phase induction motor.
- (b) Explain the electrical and mechanical characteristics of DC shunt and series motor.
- A $220 \mathrm{~V}, 1000 \mathrm{rpm}, 20 \mathrm{~A}$ dc series motor is driving at rated conditions a load whose torque is proportional to speed squared. The combined resistance of armature and field is $1.2 \Omega$. Calculate motor terminal voltag...
- (a) Explain the operation principle of four-quadrant DC chopper with circuit diagram and plot the output voltage and current waveforms.
- (b) Design and draw a simple drive circuit for power MOSFET.
- (a) Draw and discuss the steady state and switching characteristics of power MOSFET.
- (b) Explain the working principle of DC-DC step down chopper with circuit diagram and output waveform. Also derive the output voltage expression in terms of duty ratio.
- Explain the operation of a single phase fully controlled rectifier connected to RL load. With firing angle $\alpha=60^{\circ}$ and power factor of load is 0.866 draw the voltage and current waveforms across the load and switches (20)
- (a) Describe the operation of single-phase half-wave converter with RL load. Draw the voltage and current waveforms across RL load.
- (b) List any five applications of controlled rectifiers.
- Explain v/f speed control method of an induction motor drive.
- (a) Explain sinusoidal pulse modulation technique in a single phase inverter. Explain how voltage and frequency is varied using this method.
- (b) Explain single pulse width modulation technique used in single phase inverter