The 2014 winner of prestigious Goldman Environmental Prize is __?

[A]Ramesh Agarwal
[B]Srinivas Acharya
[C]Raman Choudhary
[D]Sunil Nayak



Indian environment activist Ramesh Agarwal has won the prestigious Goldman Environmental Prize that honours heroic grassroot environmentalists around the world for their achievements. He has been honoured for his contribution to control the unchecked industrial development throughout India.

The “Operation Clandestine Fox” which is in news recently, is a code name refers to _____?

[A]Searching of missing Malaysian Flight in Indian Ocean
 [B]Russian military exercise along Ukraine border
 [C]A campaign to hack the Microsoft’s internet explorer 
 [D]An operation by Indian force to check Bangladeshi migrants

What is the significance of vector grouping in Power Transformers?

Every power transformer carries a vector group listed by its manufacturer. Fundamentally it tells you the information about how the windings are connected (delta or wye) and the phase difference between the current and voltage. EG. DYN11 means Delta primary, Wye Secondary and the current is at 11 o clock referred to the voltage.

In the motors starting purpose why the armature rheostats at maximum position while the field rheostat is kept in minimum position?

In the time of starting a motor the field rheostat is kept in minimum state for the high starting torque.

In the time of starting a motor the armature rheostats is used to control or reduce the high starting current. This high starting current can damage the motors starting systems.

Name power losess in rotating electrical machines.

Power losess in rotating electrical machines are Copper losses, core losses, mechanical losses and stray losses.

Name the different types of motors used in vacuum cleaners, phonographic appliances, vending machines, refrigerators, rolling mills, lathes, power factor improvement and cranes

• Vacuum cleaners- Universal motor.
• Phonographic appliances – Hysteresis motor.
• Vending machines – Shaded pole motor.
• Refrigerators – Capacitor split phase motors.
• Rolling mills – Cumulative motors.
• Lathes – DC shunt motors.
• Power factor improvement – Synchronous motors.

Advantages of speed control using thyristor

1. Fast Switching Characterstics than MOSFET, BJT, IGBT 
2. Low cost 
3. Higher Accuracy.

4. Low power consumption. The drive is voltage controlled one rather then rheostat control.So power loss will be reduced which will improve the efficiancy

5. Easy Operation

6. No rotating parts

7. Smoother control can be possible unlike step variation in the speed in the general rheostat control

8. Wide range of control is possible with the provision of firing angle control

9.Ssize of controller will be small and the heat dissipation provisions are also not much larger as in case of rheostat controllers.

10. With the advancement of electronic devices its manufacturing cost is very much reduced so will be cheaper than the rheostatic.