Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Q. Characteristics of Transformer?
The characteristics of most interest to power engineers are voltage regulation and ef?ciency. The voltage regulation of a transformer is a measure of the change in the magnitude of the secondary voltage as the current changes from no load to full load while the primary voltage is held ?xed. This is de?ned as
in which the I2R loss is obviously load-dependent, whereas the core loss is considered to be constant and independent of the load. It can be shown that the core loss should be equal to the copper loss for maximum operating ef?ciency at a given load.
The rated core loss can be approximated by the power input in the open-circuit test in which one winding is open-circuited and rated voltage at rated frequency is applied to the other winding.
The rated copper loss (at full load) can be approximated by the power input in the short-circuit test, in which one winding is short-circuited and a reduced voltage at rated frequency is applied to the other winding such that the rated current results.
The energy ef?ciency generally taken over a 24-hour period, known as all-day ef?ciency,is also of interest. It is given by
Describe 74LS139 memory decoder. The 74LS139 is a dual 2-to-4 line decoder. This contains two separate 2-to-4 line decoders - all with its address, output and enable connection
You are the new chief PCB designer for a small company who are about to become heavily involved in the design and realisation of digital timing products. Your management wants to p
Revision of Basics Although it is assumed in this book that the reader has enough knowledge of various number systems ( binary, octal and hexadecimal and their relation
tension and sag problems
Starting Methods for Polyphase Induction Motors When high starting torques are required, a wound-rotor induction motor, with external resistances inserted in its rotor circuits
Q. Explain about 'Emitter Follower'? EMITTER FOLLOWER : An emitter follower circuit shown in the figure is widely used in AC amplification circuits. The input and output of the
give the expression
Pinch off Voltage: The current in N-JFET because of a small voltage V DS is described by: I DSS = (2a) W/L (qN d μ n V DS ) In which 2a = channel thickness
Q. Explain Modulation and sampling? Modulation is the process whereby the amplitude (or another characteristic) of a wave is varied as a function of the instantaneous value of
Q. Resultant air-gap flux of induction machine? The resultant air-gap flux is produced by the combined mmfs of the stator and rotor currents. For the sake of conceptual and ana
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd