36. Synchronous generator is operating at constant load while its excitation is adjusted to give unity pf current. If the excitation is now increased, the power factor will

1. 1. lead
      

   
   
   

   2. remain at unity

   
   
   

   3. lag

   
   
   

   4. become zero

   
   
   

---

1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   NA

---

37. Synchronous condenser means
    

1. 1. a synchronous motor with capacitor connected across startor terminal to improve

   
   
   

   2. a synchronous motor operating at full load with leading pf

   
   
   

   3. an over-excited synchronous motor partially supplying mechanical load, and also improving pf of the system to which it is connected

   
   
   

   4. an over-excited synchronous motor operating at no-load with leading pf used in large power stations for improvement of pf

   
   
   

---

1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   NA

---

---

38. In a cylindrical rotor synchronous machine, the phasor addition of startor and rotor mmf is possible because
    

1. 1. two mmfs are rotating in opposite direction

   
   
   

   2. two mmfs are rotating in same direction at different speeds

   
   
   

   3. two mmfs are stationary with respect to each other

   
   
   

   4. one mmf is stationary and the other mmf is rotating

   
   
   

---

1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   NA

---

39. In the V curve shown in the figure, for a synchronous motor, parameter of x and y coordinates are respectively
    
    

1. 1. armature current and field current
      

   
   
   

   2. power factor and field current

   
   
   

   3. armature current and torque

   
   
   

   4. torque and field current

   
   
   

---

1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: A

   NA

---

---

40. A synchronous generator connected to an infinite bus is supplying electrical power at unity p.f. to the bus. If its field current is now increased, then

1. 1. both active and reactive power output of the generator will remain unchanged
      

   
   
   

   2. active power supplied will remain unchanged but the machine will also supply lagging reactive power

   
   
   

   3. active power supplied will increase and the machine will draw leading reactive power

   
   
   

   4. active power supplied will decrease and the machine will supply leading reactive power.

   
   
   

---

1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   NA

---