STUPIDSID
Solve any one question from Q.1(a,b) &Q.2(a,b)
1(a)
Apply Mesh Analysis & determine current I1 & I2:
!mage
!mage
7 M
1(b)
Explain construction & working principle of current transformer.
5 M
2(a)
State and explain Maximum power transfer theorem.
2 M
2(b)
The following readings were obtained from O.C &S.C tests on 8 KVA, 400/120 V, 50 Hz transformer:
Calculate the voltage regulation & efficiency at full load, 0.8 P.f. lagging.
| O.C. test on LV side | 120 V | 4 A | 75 W |
| S.C. test on HV side | 9.5 V | 20 A | 110 W |
Calculate the voltage regulation & efficiency at full load, 0.8 P.f. lagging.
8 M
Solve any one question from Q.3(a,b) &Q.4(a,b)
3(a)
Explain the characteristics of D.C. shunt motor. Comment on p.f.
5 M
3(b)
Output of 3φ, 415 V Induction Motor running at 2% slip is 36.775 kW. Determine:
i) Rotor speed & Slip speed
ii) Rotor O/P & rotor copper loss
iii) Efficiency of motor at given loading conditions.
Assume Motor is wound for 4-pole & supply frequency to be 50Hz. Given friction & windage losses are 1500 W while stator losses are 3kW.
i) Rotor speed & Slip speed
ii) Rotor O/P & rotor copper loss
iii) Efficiency of motor at given loading conditions.
Assume Motor is wound for 4-pole & supply frequency to be 50Hz. Given friction & windage losses are 1500 W while stator losses are 3kW.
8 M
4(a)
Explain Torque-slip characteristics of 3φ Induction Motor. Explain the effect of Rotor resistance on its characteristics with the help of diagram.
7 M
4(b)
A 4 pole, 250 V Dc series Motor has wave connected armature winding with 1254 conductors. The flux pole is 22 mWb when the motor is taking 50 A. The armature & series field coil resistance are 0.3Ω & 0.2Ω Calculate the speed & Torque of the motor & also power developed in watts.
6 M
Solve any one question from Q.5(a,b) &Q.6(a,b)
5(a)
What are Brushless Motors? Explain with neat diagram. Explain the operation of unipolar brushless DC Motor.
6 M
5(b)
Explain construction, principle & applications of Reluctance Motor.
7 M
6(a)
Compare Brushless DC Motor with conventional DC Motor.
6 M
6(b)
What are Universal Motors? Explain speed-torque characteristics of compensated type & non-compensated type Universal Motor.
7 M
Solve any one question from Q.7(a,b) &Q.8(a,b)
7(a)
What are Stepper Motors? Explain any one type in detail. State its applications.
6 M
7(b)
Compare variable reluctance motor with permentent magnet stepper motor.
6 M
8(a)
Explain construction & working of AC Sevomotor. State its applications.
6 M
8(b)
What are Induction Motor? Explain operating principle of shaded 1φ Induction Motor.
6 M
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