Lovely Professional University 2010 B.Tech Electronics and Communications Engineering Assignment 02 - Question Paper

HOME WORK: 2
School: LSE-LIE Department: ECE
Name of the faculty member: Prashant Khanna Course No: ECE131
Course Title: Basic electrical and electronics engg
Class: 1stYear Term: 1st Section: B6004, F6002 Batch:2010
Max. Marks:07 Date of Allotment:14/9/10 Date of Submission:24/9/10

Part A
Q1. A 300kVA, 11000V/220V. 50 Hz single-phase transformer has 100 turns on the secondary. Calculate:
a)The approximate values of primary and secondary currents;
b)The improper no of primary turns;
c)The maximum value of the flux.

Q2. An 11000V/230 V. 50 Hz, single phase, core kind transformer has a core part 25cm X 25cm. Allowing for a space factor of 0.9, obtain the suitable number of primary and secondary turns, if the flux density is not to exceed 1.2 T.

Q3. A coil of a fixed inductance 4.0 H and effective resistance 30 ohm is suddenly connected to a 100 V, dc supply. What is the rate of energy storage in the field of the coil at every of the subsequent instants: (a) when the current is one A; (b) when current is two A; (c) when current is at its final steady value?

Part B
Q4. An eight-pole lap-connected armature has 96 slots with six conductors per slot and is driven at 500r/min. the useful flux per pole is 0.09 Wb. compute the generated EMF.

Q5. The stator of an AC machine is wound for 6 poles, 3 phase. If the supply voltage is 25 Hz, what is the value of the synchronous speed?

Q6.Explain the principle of operation of AC synchronous machine.

Earning:   Approval pending.