Question { 17708 }

for ac networks if the voltage wave form is V=Vm sinwt here
the voltage Vm=230 for the frequency 50hz then the time
period is 0.02 sec then for the time period 0.12 sec what
is the voltage

Answer

Ans:

Vm=230
F =50
t =0.12
pie=180
v=?
v= vm sin(2Pieft)
v= 230 sin(2*180*50*0.12) v

Question { Sail, 53147 }

What is the rating of HT SUBSTATION and LT SUBSTATION?

Answer

HT (High Tension) substation means if substation is
suppluing power to another substation is called HT
substation.(220/132 KV)

LT (low tension)substation means if substation is supplying
power to domestic and industrial usage is called LT SS. It
rating for domestic (132/11/440/0.240 KV) for industrial
(132/66/33) KV.

Question { ABB, 29126 }

Transformer's core is made up of which material and why so?

Answer

crgo is used as core in transformers to reduce iron and
frequency losses. but now a days Ampourpose is using as a
core. b'coz its thickness is very less compared to crgo and
core losses also compared to less. but little more costly.

Question { 10272 }

MCB is used for high rating &MCB is used for lower
rating.What is technical difference between ACB & MCB?

Answer

I think u want to know the difference of application
between ACB and MCB!

ACB- Air circuit breaker. it is used at incomming after
transformer secondary, b'coz at secondary side current is
more unless load is not distributed. ACB protects the
system without occuring any fault while switching on and
off of supply. B'coz it consists some mechanism to quench
the arc while occuring in system. it can used at 2500 amps.
where as in MCB(Miniature circuit breaker) there is inner
mechnism to quench the arc while operating at high
currents.that why ACB is suitable for high currents in
system.

Question { 9296 }

what factors to needed while selecting a MCB and MCCB

Answer

while selecting the MCB u have to check:
1) Current Rating.
2) Response Time.
3) Manufacturer.
4) Type of MCB (mens single pole,double pole, three pole,
four pole). depends on application.
5) Cost.

Question { 4422 }

what are the highly demanded courses for electrical engg.
who finished his b.tech

Answer

If u finshed B.Tech u better to learn PLC, SCADA, MMI and
Drive Control courses.These are very much demanded in core
industry. or other wise u better go to Embedded, Vlsi.