106. An 8-pole, 3-phase, 50 Hz induction motor is operating at a speed of 700 rpm. The frequency of the rotor current of the motor in Hz is _______
     

1. 1. 30.03

   
   
   

   2. 33.3

   
   
   

   3. 3.33

   
   
   

   4. None of the above

   
   
   

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1. View Hint View Answer Discuss in Forum

   Given, P = 9, f = 50 Hz, N = 700 rpm
   4 Frequency of Rotor current = s.f.
   

   S =	Ns - N	=	750 - 700	= 0.067
   	Ns		750

   
   ∴ f_r = (0.067) × 50 = 3.33 Hz

   Correct Option: C

   Given, P = 9, f = 50 Hz, N = 700 rpm
   4 Frequency of Rotor current = s.f.
   

   S =	Ns - N	=	750 - 700	= 0.067
   	Ns		750

   
   ∴ f_r = (0.067) × 50 = 3.33 Hz

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107. A transformer has a voltage regulation of 3% at full load, 0.8 power factor lagging. At full load unit power factor, the regulation will be

1. 1. 3%

   
   
   

   2. negative

   
   
   

   3. less than 3%

   
   
   

   4. more than 3%

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   NA

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108. The magnetizing current in a transformer is rich in

1. 1. 3rd harmonics

   
   
   

   2. 5th harmonics

   
   
   

   3. 7th harmonics

   
   
   

   4. 13th harmonics

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: A

   NA

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109. A 2-phase, 4-pole permanent magnet stepper motor has a step of

1. 1. 90°

   
   
   

   2. 45°

   
   
   

   3. 30°

   
   
   

   4. 22½°

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   NA

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110. A 400/200 V transformer has a PU impedance of 0.05. The HV side voltage required to circulate full load current during short circuit test is

1. 1. 40 V

   
   
   

   2. 20 V

   
   
   

   3. 10 V

   
   
   

   4. 5 V

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   NA

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