प्रधानमंत्री दूसरे देश के नेताओ से हॉटलाइन पर बात करते है? ये हॉटलाइन क्या है? यह आम दूरसंचार की लाइन से कैसे अलग होता है?
हॉटलाइन
दूरसंचार का वो सुरक्षित माध्यम है जो किसी दो देशों के बीच स्थापित किया
जाता है। यह एक साधारण फ़ोन लाइन होती है, पर इसका बहुत महत्व होता है
क्योंकि इस पर दो देशों के सर्वोच्च नेता (प्रधानमंत्री अथवा राष्ट्रपति)
एक दूसरे से बात करते है।
चित्र : शीत युद्ध के समय स्थापित मॉस्को-वाशिंगटन हॉटलाइन। ध्यान दें इसमें नंबर डायल नही है।
हॉटलाइन का इतिहास :
द्वितीय
विश्वयुद्ध के समय अमेरिका और ब्रिटेन के बीच एक हॉटलाइन काम कर रही थी।
यहाँ से युद्ध की महत्वपूर्ण जानकारी एक दूसरे से साझा की जाती थी।
द्वितीय
विश्व युद्ध के बाद जब अमेरिका और रूस के बीच शीत युद्ध आरंभ होता है तो
20 जून 1963 मॉस्को-वाशिंगटन हॉटलाइन स्थापित की जाती है। ये वो समय था जब
शीत युद्ध अपने चरम पर था और क्यूबा मिसाइल संकट सिर पे मंडरा रही थी।
चित्र : विभिन्न देशो के हॉटलाइन!
हॉटलाइन की विशेषताएं :
दूसरसंचार की यह लाइन मिलिट्री ग्रेड encrypted होती है और दो राजधानियों को जोड़ती है।
रिसीवर
उठाते ही दूसरे कार्यालय को फोन जाता है। मॉस्को-रूस के बीच जो फ़ोन लाइन
थी उसमें डायल भी नही था क्योंकि उस लाइन से सिर्फ एक नंबर पर ही कॉल जाती
थी। वैसे उसे नंबर कहना भी अज़ीब होगा।
इसका इस्तेमाल युद्ध और विकट आपदा की स्थिति में किया जाता है। जैसे परमाणु परीक्षण, आतंकवाद, सीमा पर क्लेश आदि स्थितियों में।
यह
हॉटलाइन दोनों देशों की आम सहमति/संधि से बनाया जाता है क्योंकि युद्ध के
समय भी नेताओ में बात होती रहनी चाहिए। यह एक जिम्मेदार देश की पहचान है!
(कृपया पाकिस्तान के संदर्भ में अर्थ न खोजें)
इसमे रियल टाइम अनुवाद की सुविधा भी होती है।
भारत की हॉटलाइन :
नई दिल्ली-इस्लामाबाद हॉटलाइन :
नई दिल्ली की एक हॉटलाइन इस्लामाबाद, पाकिस्तान से जुड़ी है। इसे 1971 के
युद्ध के बाद स्थापित किया गया। भारत और पाकिस्तान के युद्ध लड़ चुके है और
हमेशा तनाव का माहौल रहता है। ऐसे में यह हॉटलाइन तनाव कम करने का काम करती
है। भारत और पाकिस्तान इस हॉटलाइन पर कई बार बात कर चुके है!
नई दिल्ली-बीजिंग हॉटलाइन : नई
दिल्ली की एक हॉटलाइन बीजिंग से जुड़ने की भी बात चल रही है पर अभी तक इस
पर कुछ ठोस नही हो पाया है। एक DGMO स्तर की हॉटलाइन स्थापित करने की बात
अभी भी टेबल पर ही है। डोकलाम जैसे विवाद को देखते हुए यह ज़रूरी भी है।
नई दिल्ली-वाशिंगटन हॉटलाइन : जनवरी 2015में
बराक ओबामा भारत के गणतंत्र दिवस पर मुख्यातिथि बन कर आये थे। तभी यह
फैसला हुआ कि भारत और अमेरिका के बीच भी एक हॉटलाइन होनी चाहिए। अगस्त 2015
तक यह हॉटलाइन स्थापित हो गई। इसमे क्रेडिट प्रधानमंत्री मोदी की ओबामा से
दोस्ती को भी जाता है। भारत वो चौथा देश है जिसकी अमेरिका के राष्ट्रपति
के साथ हॉटलाइन है।
इसी तरह दिल्ली- मास्को के बिच भी एक हॉटलाइन है!
हॉटलाइन
का होना वैश्विक राजनीति में बहुत महत्व रखता है। किसी देश के बीच हॉटलाइन
होना उन देशों की गंभीरता को दर्शाता है कि वो बात करने के लिए तैयार हैं।
टीवी स्क्रीन पर बीच-बीच में नम्बर्स क्यों आते हैं ?
शायद आप इन नंबर की बात कर रहे है -
आप
सभी सोचते होंगे कि जब भी हम टीवी पर अपना सास बहू वाला सीरियल देख रहे है
या कोई क्रिकेट मैच देख रहे है तो ये नंबर हमारा मज़ा खराब करने क्यों आ
जाते है?
तो सबसे पहले जान ले की ये नंबर आपके सेट टॉप बॉक्स द्वारा खास आपके लिए लिखे जाते है ।
अर्थात्
अगर आप अपने घर पर कपिल शर्मा का शो देख रहे है और आपका कोई दोस्त अपने घर
पर यही शो देख रहा है तो दोनों को अलग अलग नंबर दिखाई देंगे।
दरअसल कुछ लोगो को ना अकेले शो देखने में मजा नहीं आता वो शो को रिकॉर्ड कर लेते हैं और बाद में यूट्यूब पर अपलोड कर देते है।
कुछ महाशय तो अपने टीवी से क्रिकेट मैच को लाइव स्ट्रीमिंग दिखाते है यूट्यूब पर।
इसी पायरेसी को रोकने के लिए टीवी चैनल वालो को आपको ये मूड खराब करने वाले नंबर बीच बीच में दिखाने पड़ते है।
जैसे
ही कोई शो को टीवी से रिकॉर्ड करेगा तो साथ में वो नंबर भी रिकॉर्ड हो
जाता है और अब वह उसे कई अपलोड करेगा तो वो नंबर भी वह दिखाई देगा।
इस
नंबर की मदद से टीवी कार्यक्रम को रिकॉर्ड करने वाले महाशय तक पहुंचा जा
सकता है क्योंकि ये नंबर हर सेट टॉप बॉक्स के लिए अलग दिखाई देता है।
और इसके बाद उन पर कानूनी कार्रवाई की जाती है ।
तो आगे से अकेले टीवी शो देखने की आदत डाल लें और लोगो के पास अपना टीवी है।
In this post given details of HVAC all basic information for more explanation see video in last of post. Q-Volume
Of Air is measured in?(2M)
ANS) Volume of air is measured in
terms of:
CFM = Cubic Feet per Minute
CMH = Cubic Meter per Hour
M3/Sec = Cubic
Meter per Second
L/Sec = Liters per second
CMH = 1.7 x CFM
CFM = 2118 x
m3/sec
CFM = 2.119 x l/sec
Q- What
is ASHRAE?
Answer- ASHRAE: American Society of
Heating Refrigeration and Air-conditioning Engineers
Q-What
is the Room Temperature that you maintain in any room?(1M)
Answer- 24 Degree Celsius or 76
Degree Fahrenheit
6
7 1 ton = 12000 BTU/hr = 3.516 KW.
Q-What is CFM
Answer - Cubic feet minute, it is
the unit of air flow.
CFM = Velocity(usually 1500) * Area in sqft {(d/2)^2*3.1416/144}
Q-What is Aspect Ratio?
Ans- it is the ratio between ht n
length of the duct generally we take 1:2 can vary with space and size up till
1:4.
Q-What is Collar Length?
Ans-it is the strip left at the
joining of duct and machine.
Q-12-What are the important things
to be considered before selecting devices like AHUs and Chillers:
Ans-For AHU/FCU for chilled water
system = CFM, Static pressure, Ton (capacity), Air Temp, water flow (gpm).
For AHU/FCU for direct system = CFM,
Static Pressure, Ton, Sensible.
For Chiller: Ton, outside air temp,
GPM,
Note:
(Sensible/3.4 = heating capacity.)
Static pressure to be considered to
make fan selection.
1GPM = 2.4 Ton (we need gpm in
finding pipe dia)
Q-What is Pumps supply fittings:
Ans- Thermometer, Shutoff valve,
pressure gauge, strainer, test point, drain cock, union flexible connector, and
Eccentric reducer.
Q-What is Pumps return fittings:
Ans-Eccentric reducer, flexible
connector, union test point, check valve, strainer, gate valve, check valve,
temp sensors,
Q-CFM distribution wrt the given
floor plan?
Ans-Use
ductulator.
Q-Calculating loads wrt any plan
by using software.
Ans-
Use Hap-4.32 or any to find the loads.
Q-Type of Dampers?
Ans-Fire
dampers = Butterfly damper, Non Return Damper, Motorized Damper, Fire damper,
Smoke damper, Gravity damper.
Q-Types of motorized damper?
Ans- Motorized volume damper,
Motorized fire and smoke damper.
Q-Types of grills and diffusers?
Ans = 2-way, 3-way, 4-way, 1-way,
jet diffusers with fan.
Q-What is VFD?
Ans-Variable frequency drive-it is
use to control the speed of motor by controlling the frequency applied to it.
It is used with Chillers; AHU etc. (use to control the RPM of pumps)
Q-How do you control or balance
the chilled water
Ans - Double regulating valve in
main line return (usually controlled from return using drv)
Q-How do you control the noise or
vibration in the duct
Ans- lining (nc-35) and
Rainforcement.
Q--Temperature of water at outlet
of chiller and inlet of AHU ?
@ outlet of chiller - 6-7^c & @
inlet of AHU – 7 – 8^c
@ outlet of AHU – 10 - 11^c & @
inlet of Chiller - 13-15^c.
Q--What are primary pumps and
secondary pumps?
Ans - the pumps from chiller to
building is Primary and in building transfer is Secondary.
Q- What is CFM value?
Ans-CFM = 0.417 L/s.
Q-What are the refrigerants used
in split unit?
Ans
- R22, R12, R34 (Depends).
Q-What are duct heaters and why
do we use them if we already have heating option in AHU.?
-
Just to provide heating in some
specific areas .
Q-What is VAV and its working?
= Ans- Pressure dependent
& Pressure independent:
-
To control the flow of air and temp.
(variable air volume).
-
Pressure dependent:- The volume of
air supplied by the terminal unit varies depending upon the static
pressure (SP) in the primary air duct.
-
Pressure independent terminal
units:- have flow-sensing devices that limit the flow rate through the box.
They can control the maximum and minimum cfm that can be supplied and are
therefore independent of the SP in the primary air duct.
-
Almost all HVAC systems installed or
retrofitted at present have pressure independent VAV terminals. Pressure
independent systems can be balanced and will allow the correct airflow from
each terminal.
Q-What is 3 way valve and 2 way
valve. Where we will use them and why?
Ans-2 way valve = it will regulate
the flow as per demand and it will be fitted in the return line.
3 way valve = if the AHU is closed
and is running on min load then it will by-pass (Connected to BMS).
Q-What is duct guage normally we
use in buildings for cooling and for exhaust ducts?
Ans-For supply we use 22 guage and
for exhaust we use 18 guage.
Q--What are the different method
used for duct sizing?
Ans-Equal Friction, Velocity,Static
Regain.
Q-How do you measure &
control the noise level in A/C system?
Ans-Noise level can be measured by
dB meter.It can be controlled by providing acoustic to the unit panels, if the
sound crosses the set noise criteria we have to go for sound attenuatos.
Q--What are the recommended
pressure drop in Chilled water pipes?
Ans-
210 PASCAL'S per meter (0.84 inches).
Q--Where do you use Fire
Damper,Spliter Damper & Non Return Damper?
Ans-Fire dampers (FD) are used to
stop the fire wherever duct passes thro fire wall.
Spliter dampers(SD) are used to
split the main duct for propotional air balancing
Non Return Dampers(NRD) are used to
stop the back flow of air in the duct. NRD's used in exhaust and ventilation
system only.
Q--What are the different types of
exhaust fans used to extract the air?
Ans-Axial type propeller fan,
forward curved, twin fan, direct driven centrifugal fan.
Q--What are different duct shapes
normally used?
Ans-Rectangular, Round, Spiral,
Oval.
Q--How do you control vibration of
AHU & Chillers?
Q--What do you consider while
making plant room layout explain briefly?
Ans-Space, site orientation, plant
room location, A/C unit (ready made or tailor made).
Q--Classify the different types of
chillers?
Ans-Air
Cooled & Water Cooled. With Compressors - Reciprocating,screw,centrifugal
& scroll chillers.
Q--What are the standard test
pressure for chilled water piping for Industrial application?
Ans-
Test pressure 1.5 times of working pressure.
Q--What are the Securities
checking in chillers?
Ans-Flow switch, Chiller and Pump
interlocking, High Pressure cut-out, Oil Pressure switch, High Suction
superheat, Anti Freeze.
Q-What are the temperature &
RH required for human comfort?
Ans-
22 ±2 degree celcius & 50%RH.
Q-At what temperature degree
Ferhenite & degree Celcius are same?
Ans- -40°C.
Q-Which gas is used to purge the
refrigerant line during the brazing?
Ans-Nitrogen gas.
Q-How much design velocity
required in the main duct of an office building?
Ans-900-1100 FPM
Q- How we install internal insulation
in Ducts?
And What is the insulation thickness of inside and outside
ducts?
Ans- 25mm inside and 50mm outside and ducts passing thru
unconditioned spaces.
Q-What are the different
materials used for underground chilled water supply?
Ans-Pre-insulated Black steel pipe
sch-40 with rubber cladding.
Q-How to find velocity (FPM)?
Ans-We need to know GPM and
Friction. Then coincide them in a graph and you will get velocity. And
for chilled water we need to know no. of cycles per year (in
ksa=6months*30days*24hrs = 4320)
search for this value in the annexure of
ashrae to find the FPM.
The fpm you get will be for the roof , to get the fpm
in risers take 20% of roof and to get in runners take 20% of risers.
Q- What Is The Fcu?
A Fan Coil Unit (FCU) is a simple
device consisting of a heating and/or cooling heat exchanger or 'coil' and fan.
It is part of an HVAC system found in residential, commercial, and industrial
buildings
Q-What Is The Function Of Ahu?
An Air Handling Unit (AHU) is used
to re-condition and circulate air as part of a heating, ventilating and air-
conditioning system. The basic function of the AHU is take in outside air,
re-condition it and supply it as fresh air to a building.
Q- What Are The Types Of Air
Conditioning Systems?
Types of Air Conditioning Systems
The choice of which air conditioner system to use depends upon a number of
factors including how large the area is to be cooled, the total heat generated
inside the enclosed area, etc.
• Window Air Conditioner.
• Split Air Conditioner.
• Packaged Air Conditioner.
• Central Air Conditioning System.
Q- What Does A Hvac Engineer Do?
An HVAC engineer's job duties can
include the design, installation, maintenance, and repair of heating,
ventilation, air conditioning, cooling, and refrigeration systems.
Q- What Is The Hvac System?
While the Energy Center usually
tries to avoid the use of acronyms, HVAC is in common use in the heating and
cooling industry. It stands for "heating, ventilation and air conditioning,"
three functions often combined into one system in today's modern homes and
buildings
Q-What Is The Meaning Of Btu In Air
Conditioners?
Btu – British Thermal Unit (Btu) is
the international measure of energy. A Btu is the amount of heat needed to
raise 1 (one) pound of water by 1(one) degree Fahrenheit. In HVAC industry,
Btu's measure the quantity of heat a conditioning unit can remove from a room
per hours. One BTU per hour is equal to 0293 watts
Q-What Is Centralised Air System?
The most common central cooling
system is a split system, which includes an outdoor cabinet containing a
condenser coil and compressor, and an indoor evaporator coil, usually installed
in conjunction with your furnace. or air handler . The compressor pumps a
chemical called refrigerant through the system
Q-What Is The Meaning Of Fahu?
FAHU is the abbreviation used for
FRESH AIR HANDLING UNIT. These are usually centralized units employed to induce
fresh air quantities to the confines spaces. They come into picture wherever
there are limitations to fresh air intake either directly or through AHUs.
Question 1. What Will Be The
Relative Humidity At Saturation Point?
Answer :
Relative humidity = 100 %
·Question 2. Explain The Principle Of
Refrigeration?
Answer :
The operation is according to the
second law of thermodynamics - Heat can be made to flow from cold body to hot
body with the help of external source.
·Question 3. What Is Air Conditioners?
Answer :
Air Conditioner continuously draws
the air from the space to be cooled & cools it by the principle of
refrigeration and discharge it back to the same indoor space that need to be
cooled.
·Question 4. What Is Wet Bulb Depression?
Answer :
Wet bulb depression is the
difference between dry bulb temperature and wet bulb temperature.
·Question 5. Define Relative Humidity?
Answer :
Relative humidity is the ratio
between the actual moisture content of the air compared with the moisture
content of the air required for saturation at the same temperature.
·Question 6. What Is Refrigeration?
Answer :
Refrigeration is the process of
continuously cooling or extraction of heat from the atmosphere or surroundings
with the help of external work.
·Question 7. Difference Between The
Refrigeration And Heat Pump?
Answer :
Refrigerators ejects heat with work
input. But heat pumps gives heat with work input.
Refrigerator contains the heat pump,
it pumps the heat out so that your system remains cold.
·Question 8. What Is Sensible Heat Ratio
(shr)?
Answer :
The Sensible Heat Ratio (SHR)
express the ratio between the sensible heat load and the total heat load.
·Question 9. How Much Resistance Is Offered
To Heat Flow By Dropwise Condensation?
Answer :
Nill.
·Question 10. Why Rate Of Condensation Is
Higher On A Polished Surface Compared To Rusty Surface?
Answer :
Polished surface promotes drop wise condensation
and does not wet the surface.
·Question 11. What Is Mechanical
Refrigeration ?
Answer :
Producing cold by machine.
·Question 12. Classify The Different
Refrigeration Systems?
Answer :
It may be of the following three
types:
Vapor Compression Refrigeration System
Vapor absorption Refrigeration System
Air Refrigeration Systems
·Question 13. What Are The Basic Units Of
Mechanical Refrigeration Systems?
Answer :
Refrigeration system has 4 basic
units
An Evaporator – The cooling Unit
A pump or Compressor
A Condenser – The heat disposer
A liquid mixing device – Expansion valve or cylinder or
capillary tube
·Question 14. Which Unit Produces Cooling
Effect In The Refrigeration System ?
Answer :
The evaporator
·Question 15. What Is The Unit Of
Refrigeration?
Answer :
As Power Unit of mechanical devices
is given by H.P , for electrical equipment the unit of power is kW or MW . In
the same way the unit of refrigeration is ” Tonnes of Refrigeration ”
·Question 16. What Is One Tonne Of
Refrigeration ?
Answer :
One Tonne of Refrigeration means
machine is capable of removing heat from a body equal to the heat absorbed by
one tonne of ice when it melts from 0 ° C to 0 ° C Water in 24 hours . Here one
tonne is equal to 2000 lb .
·Question 17. What Is The Capacity Of One
Tonne Machine In Mks System?
Answer :
In MKS system a machine having
capacity to produce cooling effect of 50 kcal/minute is known to be a “One
Tonne Machine”
·Question 18. Define Co-efficient Of
Performance?
Answer :
In case of engine the performance is
judged the efficiency of the engine. That is – Efficiency = Work Done / Heat
Supplied .
And in case of refrigeration the
process is first reversed that is we have to supply work to obtain lower
temperature or say for that removal of heat. Thus performance of
refrigeration is just reversed . That is – N/W
Where – N = The rate of heat
abstracted from the body in given time technically called “Net Refrigeration
Effect” and W = Work Done .
Thus COP = Net Refrigeration Effect
/ Work Done Supplied . This is Called Theoretical COP .
इस वीडियो में उत्तर के साथ सिंगल फेज एसी मोटर संबंधित साक्षात्कार प्रश्न है, जो अधिकतर साक्षात्कार में पूछा जाता है। Single phase motor rotation direction change.
Single phase motor self starting.
Which motor work on unity