Power Electronics Test 1 EE2425B

[3 minutes] Fill in the blank .
Power Electronics  circuits involve______________ from one form to another using power semiconductor devices  (1 mark)

• converting mechanical power
• transfer heat
• converting electrical power
• converting electromagnetic field

[3 minutes] Application of power electronics in drive system is...... (2 marks)

• to convert electrical charge for supplying load demand or for Power Quality (PQ) improvement.
• to convert electrical power for supplying load demand or for Power Quality (PQ) improvement.
• to manipulate certain parameter for controlling the weight of motors.
• to manipulate certain parameter for controlling the speed of motors.

[3 minutes] How to increase the reverse blocking capability of diode? (1 mark)

• connect several diodes in parallel
• connect several diodes in series

[3 minutes] The current gain, β of BJT is given by the expression (1 mark)

• I_C/I_B
• I_C/I_E
• I_B/I_C
• I_E/I_G

[3 minutes] The controlling parameter in IGBT is the......(1 mark)

• I_G
• V_GS
• I_D
• V_GE

[3 minutes] For an SCR in the REVERSE BLOCKING MODE, (practically)...... (1 mark)

• leakage current flows from anode to cathode
• no leakage current
• leakage current flows from cathode to gate
• leakage current flows from cathode to anode

[3 minutes] Three types of common  power transistor are.....(1 mark)

• Diode, Triac and IGBT
• BJT, MOSFET and IGBT
• Diode, IGBT and GTO
• GTO, MOSFET and IGBT

[5 minutes] A single-phase half-wave type diode rectifier requires __________ number of diode(s) whereas full wave type requires _________ number of diode(s) (2 mark)

• 4, 1
• 1, 4
• 1, 3
• 3, 4

[5 minutes] For a certain diode based rectifier, the output voltage (average value) is given by the equation 1/2π ∫V_m sin (ωt) dωt ; where the integral (∫) runs from 0 to π. The rectifier configuration must be that of a.... (2 marks)

• single phase controlled full wave with R load
• single phase uncontrolled full wave with R load
• single phase uncontrolled half wave with RL load
• single phase uncontrolled half wave with R load

[5 minutes] A single-phase full wave rectifier is a..... (2 marks)

• multiple pulse rectifier
• single pulse rectifier
• two pulse rectifier
• three pulse rectifier