Electrical Science Flashcards
What circumstance would you get current flow in neutral
Unbalanced load causing the return path to carry current
Application of dc motor
Cranes
Hoist
Trams / trains
Conveyors
Production of electricity from a fossil fuel
Burn coal,gas and oil
Heat water to steam
Steam drives turbines
Turbines turns to coil generating electricity
Operation of an electric storage heater
Heat retaining clay bricks inside the storage heater are charged over night by a heating element to store heat and release heat during the day economy 7 electricity is used at night
How does a single transformer work
Current in primary produces magnetic flux in transformer core this flux circulates , an emf is induced in the secondary coil
Electric space heating
Heat from a heating element is stored
Full wave rectification
Makes use of both half cycles of input alternating current ac and converts them to direct current dc
P.f.
Kw \kva
Kva
I * v / 1000
Consumer installation begin
Live conductor from metre
3 ways to generate electricity
Burning fossil fuels
Wind turbines
Solar panels
Voltages for generation, transmission and distribution
25kv , 132-400kv , 66kv and below
What is the effect of an energised coil on a compass
A compass needle will swing through 90 degrees and will a line with magnetic field
Operation of a suitable starter
Feed back loop to maintain constant speed
Star
IL =Ip
VL = root 3 x vp
