176. A three-bus network is shown in the figure below indicating the p.u. impedances of each element.
     
     The Bus admittance matrix, Y-bus, of the network is

1. 1. j		0.3		-0.2		0
      		-0.2		0.12		0.08
      		0		0.08		0.02

   
   
   

   2. j		-15		5		0
      		5		7.5		-12.5
      		0		-12.5		2.5

   
   
   

   3. j		0.1		0.2		0
      		0.2		0.12		-0.08
      		0		-0.08		0.10

   
   
   

   4. j		-10		5		0
      		5		7.5		12.5
      		0		12.5		-10

   
   
   

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1. View Hint View Answer Discuss in Forum

   Y11 =	1	+	1	= - j15
   	j0.1		j0.2

   Correct Option: B

   Y11 =	1	+	1	= - j15
   	j0.1		j0.2

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177. A load center of 120 MW derives power from two power stations connected by 220 kV transmission lines of 25 km and 75 km as shown in the figure below. The three generators G1, G2 and G3 are to 100 MW capacity each and have identical fuel cost characteristics. The minimum loss generation schedule for supplying the 120 MW load is
     

1. 1. P1 = 80 MW + losses
      P2 = 20 MW
      P3 = 20 MW

   
   
   

   2. P1 = 60 MW
      P2 = 30 MW + losses
      P3 = 30 MW

   
   
   

   3. P1 = 40 MW
      P2 = 40 MW
      P3 = 40 MW + losses

   
   
   

   4. P1 = 30 MW + losses
      P2 = 45 MW
      P3 = 45 MW

   
   
   

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1. View Hint View Answer Discuss in Forum

   Loss ∝ p²
   Loss ∝ length For checking all options only option (a) gives less losses.

   Correct Option: A

   Loss ∝ p²
   Loss ∝ length For checking all options only option (a) gives less losses.

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178. For enhancing the power transmission in a long EH V transmission line, the most preferred method is to connect a

1. 1. series inductive compensator in the line

   
   
   

   2. shunt inductive compensator at the receiving end

   
   
   

   3. series capacitive compensator in the line

   
   
   

   4. shunt capacitive compensator at the sending end

   
   
   

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1. View Hint View Answer Discuss in Forum

   P ∝	1
   	X

   
   where, X = (X_L – X_C)

   Correct Option: C

   P ∝	1
   	X

   
   where, X = (X_L – X_C)

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179. A negative sequence relay is commonly used to protect

1. 1. an alternator

   
   
   

   2. a transformer

   
   
   

   3. a transmission line

   
   
   

   4. a bus bar

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: A

   NA

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180. A nuclear power station of 500 MW capacity is located at 300 km away from a load center. Select the most suitable power evacuation transmission configuration among the following options

1. 1. 

   
   
   

   2. 

   
   
   

   3. 

   
   
   

   4. 

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: A

   NA

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