Notes on Electrical system-2

• Purpose of Trickle charging of batteries- To keep it fresh and fully charged.
• Capacity of Lead-acid battery doesnt' depends upon- Rate of charge.
• Internal resistance of battery is reduced by-  a)Increase the size of the plate,

                                                                             b) Multiply the number of plates,                                                                                                                  c) Interlacing of plates.

• Efficiency of battery is increased by- 5 hour Discharge Rate.
• Batteries are rapidly charged by- Constant Voltage & Variable Current.
• Neutralizing agent of Lead-acid battery are- Baking Soda & Water.
• The electrolyte in Ni-Cd batteries performs work as a- Conductor, but not take part in chemical                                                                                               reaction.  
• Electrolyte in Ni-Cd battery is- Pottasium Hydroxide( KoH).
• CSD( Constant Speed Drive) is disconnected - Electromechanically.
•  In CSD, the UNDERDRIVE condition, pressure will be- Increases.
• Main purpose of using core in a transformer--- Decrease reluctance of common magnetic circuit.
• Transformer is not used as an Amplifier because- It doesn't provide Power Gain.
• Lamination of a transformer depends upon-- Frequency.
• An electric motor in which both the rotor and the stator field rotates with the same speed is called--                                                                                                                          Synchronous Motor.
• For parallel operation, AC polyphase altenator must have the same-- Voltage Rating.
• What will happen, if we interchange two phases of a three phase induction motor?-- The direction of rotation will be reversed.
• Type of motor used in direct cranking of engine-- DC Series Wound.
• Thickness of laminations reduced in a transformer to- Reduce Eddy Current.
• Operating current of LED-- 20 to 30 mA.
• In Double squirrel cage Induction motor the outer stage has-- High Resistance.
• Electrostatic Voltmeter measures-- AC & DC.
• An aircraft battery requires frequent addition of water due to-- Leakage & Defective cell.
• What is the value of capacitor with colour coding Red, Green,Black & Grey?-- 25pF
• The average value of unsymmetrical alternating current is considered across- 1 Complete Cycle. 
• What is not essential condition for parallel operation of 2 one phase transformer, is that they should have the --- Same Polarity.
• If the primary of step-up transformer is connected to load by mistake and secondary is supplied with voltage--- It will act as step-down transformer.
• Operation of LCD-- It doesn't emit light & depends on light falling on it.
• In a PN junction, the depletion layer is formed due to-- Mobilization of majority carrier.
• The APU serves the purpose of- Supplying electrical and pneumatic power as required.
• The main field of the generator in the brushless alternator is excited from-- Field connected to the rotating rectifier.
• Flashing of field is not required in brushless alternator because Percent voltage build up is achieved by--DC supply from GCU, is supplied continuously.
• A VTVM produces negligible loading effect on a circuit under a test because- Of its very high internal resistance.
• When servicing a DC generator, a dark film is found on commutator--It should be cleaned with no.000 sand paper.
• The dirt on the NI-Cd battery is cleaned with- De mineralized water.
• The meter used to measure the voltage of individual cells of the battery-- Normal Voltmeter.
• In CRO, what actually is done by varying intensity control-- Negative Grid base.