Maharashi Dayanand University (MDU) 2009-1st Sem B.Tech Electronics and Communications Engineering "f scheme" - , electrical technology - Question Paper

B.tech first semester exam - december 2009
ELECTRICAL TECHNOLOGY

NOTE: attempt any 5 ques..

1. (a) State kirchoff's laws of current and voltage. three
(b) State maximum power transfer theorem. 3
(c) elaborate crest and peak factor ? 3
(d) elaborate unbalanced circuits ? 3
(e) elaborate eddy currents ? 3
(f) elaborate cut-off frequences ? three
(g) discuss , what is slip ? 3

2.(a) Derive expression for converting delta circuits to star circuits. 10
(b) Differentiate between: 10
(1) lumped parameter and distributed parameters,
(2) mesh and loop,
(3) active and passive components and sources.

3. (a) State and discuss thevenin's theorem. 10
(b) State and discuss milbman's theorem. 10

4. (a) discuss the behaviour of R - C circuits to step response. 10
(b) discuss the concept of voltage and current in RL ,RC and RLC circuits with the help of phasor diagrams. 10


5.(a) Derive outcomes of resonant frequency , bandwidth and impedence un case of series RLC circuits.
10
(b) Derive relation ranging from lc and lph, vc and vph in case of star connected 3 phase circuits.
10


6. (a)Explain how 3 phase power can be measured by 2 wattmeter method? 10
(b) Draw and discuss the construction of transformer and derive emf formula. 10


7. (a) discuss how S.C test is performed and why ? 10
(b) Draw and discuss the phasor diagram of transformer with no load and full load. 10


8. (a) discuss the construcction and working of synchronous motor. 10
(b) discuss the working principle of D.C machine and derive emf. formula for it . 10

9. Write short note on :
(a) Induction kind voltmeter, 10
(b) Energy Meter. 10

Earning:   Approval pending.