Already have an account? Get multiple benefits of using own account!
Login in your account..!
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. What do you mean by Phase Sequence?
It is standard practice in the United States to designate the phase A-B-C such that under balanced conditions the voltage and current in the A-phase lead in time the voltage and current in the B-phase by 120° and in the C-phase by 240°. This is known as positive phase sequence A-B-C. The phase sequence should be observed either from the waveforms in the time domain shown in Figure (a) or from the phasor diagrams shown in Figure (b), and not from space or schematic diagrams, such as Figures (a). If the rotation of the generator of Figure is reversed, or if any two of the three leads from the armature (not counting the neutral) to the generator terminals are reversed, the phase sequence becomes A-C-B (or C-B-A or B-A-C), which is known as negative phase sequence.
Only the balanced three-phase sources are considered in this chapter. Selection of one voltage as the reference with a phase angle of zero determines the phase angle of all the other voltages in the system for a given phase sequence. As indicated before, the reference phasor is chosen arbitrarily for convenience. In Figure(b), ¯VBC is the reference phasor, and with the counterclockwise rotation (assumed positive) of all the phasors at the same frequency, the
sequence can be seen to be A-B-C. Unless otherwise mentioned, the positive phase sequence is to be assumed.
Methods of Testing Irrespective of reasons, testing is commonly carried out 1. On site, or 2. In a Meter Testing Station (MTS) accredited as per IS/ISO/IEC 17025.
Q. A magnetic force exists between two adjacent, parallel current-carryingwires. Let I1 and I2 be the currents carried by the wires, and r the separation between them.
Q. Draw the circuit of a common drain FET amplifier and explain. FET amplifier circuit The weak signal is applied between gate and source and amplified output is obtained
Draw and explain the block diagram of DMA controller. The fundamental idea of DMA is to transfer blocks of data directly between peripherals and memory. The data don't suffer t
Determine the resistance and temperature-coefficient: A platinum coil has a resistance of 3.146 Ω at 40 o C and 3.767 Ω at 100 o C. Determine the resistance at 0 o C and the t
Turn off Time This is also known as gate controlled turn on time. The time interval between a specified point at the beginning of the gate pulse and the instant wh
GIS Benefits: Improving financial viability. Reduction of T&D losses. Improving customer satisfaction. Raising reliability of power supply. Improving qual
Q. A toroid with a circular cross section is shown in Figure. It is made from cast steel with a relative permeability of 2500. The magnetic flux density in the core is 1.25 Tmeasur
what is circular convolution
Calculate the following for a 2 hp and a 20 hp dc machine, each rated for 500 rpm. Use data from the Study Plan 1 data sheet, including "hot" armature resistance value for all cal
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!
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd