CULTURALQA 09-2021-19
Beingcompilation there may be errors
Q1 Whydo circuit breakers respond quicker than fuses?
A1 RonDavis Studied electronics as part of a Ph. D. in physics.
February 26
Before you ask “why”,ask “whether”.
Both fuses and circuit breakers come in “fast-blow” and“slow-blow”, or
“fast-trip” and “slow-trip” types. There are of course alsomore specific,
numerical descriptions, in terms of specific over currents, andcorresponding
delay times, that the fuse or breaker will wait before trippingin response
thereto.
Most circuits require some delay in response to an over current.Incandescent
bulbs, for example, have about a tenth of the resistance when coldthat they
have in steady operation, so on start up draw about ten times theirsteady
current, typically for half a cycle of an AC supply.
Electric motors also draw higher current while coming up tospeed from a
standing start than they do in steady operation, and the excesscurrent may be
drawn for several seconds.
Indeed, most appliances draw a higher current during startupthan during steady
operation, so their supply circuits would be useless if theydid not tolerate
the brief over currents that occur during start up.
A seeming alternative might be that a circuit were designedthat could carry
steadily a current that occurs only during start up. However,it would be
wastefully overdesigned. Instead, a well designed circuit can passbrief over
currents, even though they would be in danger if those currentspersisted. This
ability follows from the heat capacities of the conductors andjunction boxes,
and from physical separation between the conductors, in whichthe heat is
created, and nearby, temperature-sensitive materials, such as woodframing.
Also, typical appliances, even though they are of course ableto withstand their
own high start up currents, need to be protected against the possibility that
thehigh start up currents persist too long. Many appliances havebuilt-in
circuit breakers for this purpose. Others rely on standardized supplycircuits,
which must therefore feed such an appliance through a dedicatedbranch circuit.
Those are the motivations for varying rapidity of response tobrief over
currents, but a related question is how fuses and circuit breakersare made to
have the appropriate rapidity of response.
Fuses and typical circuit breakers work by having the currentpass through a
conductor inside, which has some resistance, so that the current generatesheat
in the conductor, at a rate that is greater as the current isgreater. The
resistance is of course small, compared with the impedance of theload, so that
little power is consumed by the element.
The resisting element may be fine but short, or longer butfatter, to have the
same resistance. With the same resistance, the rate ofgeneration of heat will
be the same. However, with a longer, fatter resistor,the amount of material to
be heated is greater. Thus, a finer resistor makes for fastblow, and a fatter
resistor makes for slow blow.
In a fuse, the mechanismthat breaks the circuit is that the resisting element
melts, and then surfacetension draws the material away from the middle.
In most circuit breakers, the resistor consists of sheets oftwo different
metals, bonded together face-to-face. The metals have differentcoefficients of
expansion in response to heating, so that the unstressedcurvature of the metal
changes. The metal is configured under stress so that,when at ambient
temperature, it is stable in two different shapes,corresponding to off and on.
When hot, the metal is stable only in the offposition, so it makes anabrupt
transition thereto when its temperature is at the tripping point.
Of course, there are also more sophisticated circuitbreakers, which measure the
current electronically, and perform analog ordigital calculations of its recent
history to decide whether to break thecircuit, which they then do by
electromechanical means. These range up tomainframe computers that regulate
large distribution networks on the basis ofreadings tele metered from locations
throughout the network, and send on-offsignals to correspondingly distant
switches.
Q2 Why does Bengaluru have such anice climate whereas in Chennai
it is hot/humid when both are at the same latitude and300km apart?
A2 Subramaniam Duraisamy Lives in Chennai, Tamil Nadu,India Tue
|
|
|
| | |
|
|
|
| |
Why does Bengaluru have such a nice climate whereas in Chennai it is hot...
Subramaniam Duraisamy (சுப்பிரமணியம் துரைசாமி)'s answer: Bangalore is located
at midpoint between the east coast...
|
|
|
Bangalore is located at midpoint between the eastcoast and west coast. In the
below map you can see the areal distance betweenChennai and Bangalore and then
Bangalore and Mangalore.
Being at the dead center it gets rains from boththe Western arm and Eastern arm
of the monsoon
Coupled with it is the altitude. Bangalore islocated at an altitude of 900 m
above sea-level and thus itsrelative humidity is much lower than Chennai which
is a coastal city.
Amongst the South Indian cities, Bangalore is theone amongst lowest RH
levels.All this makes Bangalore a cooler city thanChennai.
Q3 Doyou prefer to eat your dinner on a sofa with a coffee table
in front of you orwould you rather sit at a dining table?
A3 KrutiNaik Writer, Government Servant & former journalist Tue
Neither on sofa, nor on a dining table. I prefer eating myfood sitting cross
legged on the floor.
One of the reasons is also because I live in a rented placeand I have not yet
spent money on buying a dining table for three reasons:
Sitting on floor cross legged helps muscles in abdomen tosecrete digestive
juices, and helps digesting the food quickly. It alsoimproves body posture.
People who often complain about gastric and acidityissues after having food
should sit on floor for at least 10 minutes once theyfinish their food.
It makes the human in us more humble. I think sitting onfloor strengthens the
spiritual side of us. It also kind of make us moreconnected to our mother land.
It saves me Money. Initially, when I shifted to this place, Idid go look for
buying a dining table. The ones I liked were pretty muchexpensive around 40k, I
did not want to spend that much on a dining table.
My note- In thepresent days, I use dining table because I feel difficulty in
getting up after taking food
Q4 Whyare there so many North Indians migrating/living in the
South but there hardlyany or close to 0 South Indians in the North India?
A4 DineshBinjola Lives in Delhi NCR Updated August 4
Well, it is obvious that you have never visited any place inthe “North India”.
It is estimated that Delhi City itself has half a millionTamilians and then you
may add the people from other Southern States too. Inall, it may be over a few
millions.
Just see these few pictures from Delhi.These images might helpto add to your
awareness.This is Uttara Swami Malai Mandir, Rama Krishna Puram,in the heart of
New Delhi.(PICTURESNOT ADDED)
Note : There are many more such temples in Delhi which aremanaged by South
Indian societies. See photos of Sri Ram Temple, Lodhi Road,New Delhi, in
comment below.
Once we lived in Janakpuri (New Delhi). A Tamil family wasliving on the same
floor. We used to visit Shree Rajrajeshwari Devi Temple withthem which was near
our residence.
This is a school in Delhi run by DTEA. There are 5 - 6 moresuch DTEA schools in
Delhi.
You may read the names on the sign boards of the shops.
See the name of this restaurant located in a market nearDelhi University.
This is a saree showroom in New Delhi. The name is known toall South Indians.
This is Uttara Guruvayurappan Temple, Mayur Vihar, EastDelhi.
This is not “South Indian Food”. We prepare these items athome every now and
then.
Thanks to the owners of all the nice images used here. PICTURES NOT ADDED
My note- Similar is thecase with Mumbai and Calcutta, Bhopal etc.
Q5 Whywon't your AC cool your home more than 20 degrees?
Robert Pattison , I have lived and worked in severalcountries and read widely
.Answered 1h ago
Your house is not insulated enough to prevent the flow ofheat coming in.
Q6 Whatare some interesting facts about Saudi Arabia?
A6 PhillipGabriel Alcantara MercadoStudied Cold War History and
South East Asian History.Updated January 12
The world’s longest, andpossibly most boring, straight road is in Saudi Arabia!
This is Highway 10.Located in Saudi Arabia. It is the world’s longest straight
road, measuring inat 250–256km in distance. According to Google Maps, it will
take between an hour and 57 minutesor two hours and four minutes to travel down
the straight road.
Furthermore, it is probably one of the most boring roads outthere as it only
cuts through desert, desert, and even more desert! Though ifyou like deserts
and sand dunes, maybe this road won’t be as boring foryou.~Phillip Mercado
Footnotes
[1] This Saudi highway is the world's longest straight road
Q7 Whydoesn’t Andhra Pradesh have a Rajadhani Express?
A7 MathiSelvakumar Arumugam An ardent rail fanSeptember 12
After the original AP express was renamed as Telenganaexpress, in 2015 a new
Andra pradesh AC express was introduced. Currently itruns with 13AC coaches
and6 Sleeper coaches in addition between Vishakapatnam and New Delhi.
This train was intended for a dual purpose of replacing theold AP express and
serving as premium train.
Q8 Whyshould you not plug in too many appliances in the same
outlet in a home?
A8 3 Answers Ronald Forrester,Various PositionsNatural Gas
Pipeline Industry (1984-present) Answered Tue
The simple answer is you may overload the circuit, which ifeverything goes as
it should, will trip the breaker for that circuit. However,if things go wrong,
such as someone has modified the circuit incorrectly, itcould mean an
electrical fire and or damage to whatever is plugged into thatcircuit. Keep in
mindany one circuit may have 5 outlets on it, and the circuit is likely 15 or
20amps. This means you must consider all devices plugged into alloutlets on
that circuit. There are a lot of variables, such as the age of thebuilding and
your geographical location, but this should help.
2nd answer-Shane Gieger , former Electrical Superintendent (2016-2020) Answered
September 13
Due to over heating a device and causing a fire from theheat. Loose
connectionsare the leading factor for fire damage in my opinion. I have seen
wirescompletely burnt into in panels due to an installer failing to torque lugs
tospecifications or due to maintenance not returning to the panel and
retourqeing lugs after a proper amount of time of system coming on line.
Retorquing is nessarywhen new systems are brought on line as heat effects
everything in life the Eiffel Tower growsand srinks by feet yearly due to heat.
Wire also grows or shrinks depending ontemperature and electrical devices and
wiring heats up upon the usage of poweror amps more amps more heat this may
require adjustments be made in the systemto allow for lesser restance ie wire
size dependant upon ambient tempture dueto location upon the earth. Or pipe
additions such as expansion joints toprevent bowing of wire paths and to reduce
the path from separating atconnections or of pushing at these connections as
well I have seen pvc ran witha laser stright after install and clamped per NEC
and upon summer coming lookas though a child had installed it having a snake
like appearance to it due tothe fact that expansion joints were not installed
well other than at deckseparation points per NEC and due to movement in the
deck from hurricanes iecoastal areas. Heat can be an issue due loose old
connections at outlets fromussuage over time having caused separation at the
blades of the outlets theseloose connections can cause heat to build and other
factors added to thesituation thus causing a continually growing determination
of the system andparts and devices use within the system. If a busing or
humming sound is heardplease always call a professional as a humming or buzzing
is a sure sign ofaoose connection the professional should use a thermal imager
in his anlaisesof the system if the sound is not found a call for another
opinion as allservicemen are not of the same caliper and your family's safety
is your concernand this buzzing or humming could very well lead to a fire
3rd answer-GopalaKrishnan , former Assistant General Manager 1996-2004 at
Department of Telecom (1966-2004) Answeredjust now
In India we use extension board for 5 amps/15 amps socket. Weset a limit to
ensure not mere than five amps/15amps aredrawn at a time from the extension
board.
In my room LCD TV 37 inches with setup box, my laptop and onemore equipment are
connected to a 15 amps box. Some times electrical iron isconnected after
removing Lapop
Q9 Whichis the most beautiful temple in India?
A9 AshwinIyer have interest in Indian history Tue
India is a wonderful place for anyone who loves architecture.Indian temples
come in a lot of variety - the styles vary from place to place.We have the
so-called “Dravidian” architecture which includes temples of TN,Karnataka and
Andhra Pradesh, the unique North Indian style of temples, simpleand elegant
Kerala temples and much more.
It would be a grave injustice to choose one temple in Indiaand call it the most
beautiful. So what I’ll be giving is just one temple,which looks awesome, not
the “most beautiful”.
As a South Indian myself, of course I would love South Indianarchitecture. But
since the answers are full of them and South Indian templesare in no way
underrated, can we go on a trip to Rajasthan?
Kiradu (किराड़ू)
It looks absolutely stunning, right? The Kiradu temples are agroup of temples
in present-day Rajasthan (in the town of Kiradu, a few milesfrom Barmer). These
temples are in ruins now but still they look so beautiful,just imagine how they
would have been at that time!
The temple was built in the 11th-12th centuries by theSolanki kings of
Rajasthan. We have 5 temples as of now in Kiradu.
Some inscriptions too survive, but I am not able to get thecontents of the
inscriptions on the internet. Wikipedia does say it mentionsrepairs done after
attempts of destruction by the Turks (Ghurid invasion headedby Muhammad of
Ghor), but I couldn’t get much. If anyone knows the contents ofthe
inscriptions, kindly comment below.
Kiradu was originally known as either Kiratakupa or Kiratakipa.Justsee the
beauty and the intricacy in the sculptures of the pillars!
The beauty is unparalleled.There is a story that if one goes alone after
sunset,he/she will turn into stone. Unfortunately, most pieces of
internetavailable on the temple focus on the “horror” (and superstition) part
more thanthe architecture, inscriptions or history. I guess people love such
sillythings more :I would really love to go to this place!
All the above QA are basedon Quora digest to me on 18-09-2021. Quora answers
need not be 100% correctanswers
Compiler- R. GopalaKrishnan, 77 dated 19-09-2021
--
You received this message because you are subscribed to the Google Groups
"Thatha_Patty" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To view this discussion on the web visit
https://groups.google.com/d/msgid/thatha_patty/1757555844.1100934.1632019714429%40mail.yahoo.com.
