First Paying Customer to #dearmoon of SpaceX

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ssc je questions

1. To measure static pressure in pipe , one uses a pressure guage connected to a:
A) pitot tube
B) venturimeter
C) orificemeter
D) pitometer tapping

2. The flow in open channel is turbulent if the Reynolds numbers is :
A) 2000
B) more than 2000
C) more than 4000
D) 4000

3. A submerged weir is one in which the water level the down sreams side of weir is:
A) Just at crest level
B) below the crest level
C) above crest level
D) at same elevation as water surface on upstream

4. Uniformity coefficient of soil is :
A) always less than 1
B) always equal to 1
C) equal to or less than 1
D) equal to or greater than 1

5. Flow of fluid takes place due to its :
A) Viscosity
B) Compressibility
C) Surface tension
D) Deformation under shear force

6. The magnitude of the buoyant force can be determined by :
A) newton’s law of viscosity
B) archimede’s principle
C) principles of moments
D) none of the above

7. Quick sand is a:
A) type of sand
B) flow condition occurring in cohesive soil
C) flow conditions occurring in cohesional soils
D) all of the above

8. The pitot tube is used to measure:
A) Velocity at stagnation point
B) Stagnation pressure
C) Static pressure
D) Dynamic pressure

1) A   2) B   3) C   4)D    5) D   6) B   7) C   8)

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Igneous Rocks

Igneous rocks: The inside portion of the earth’s surface has high temperature so as to cause fusion by heat at even ordinary pressures. The molten or pasty rocky material is known as the magma and this magma occasionally tries to come out to the earth’s surface through cracks or weak portions.

The rocks which are formed b the cooling of magma are known as the igneous rocks.

The igneous rocks are recognized in the following three classes;

(a) plutonic rocks: Such rocks are formed due to cooling of magma at a considerable death from earth’s surface. The cooling is slow and the rocks possess coarsely grained crystalline structure.

The igneous rocks commonly used in building industry are of plutonic type. The granite is the leading example of this type of rock.

(b) Hypabyssal rocks: Such rocks are formed due to cooling of magma at a relatively shallow depth from the earth’s surface. The cooling is

quick and hence these rocks possess finely grained crystalline structure. The dolerite is an example of this type of rock.

(c) Volcanic rocks: Such rocks are formed due to pouring of magma at earth’s surface. The cooling is very rapid as compared to the previous two cases. Hence these rocks are extremely fine grained in structure. They frequently contain some quantity of glass which is a non-crystalline material. The basalt is an example of this type of rock.

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Spillway- In Dams

A  spillway is a structure constructed at a dam site, for effectively disposing of the surplus water from upstream to downstream. Just after the reservoir gets filled up, up to the normal pool level, water starts flowing over the top of the spillway crest (which is generally kept at normal pool level). Depending upon the inflow rate, water will start rising above the normal pool level, and at the same time, it will be let off over the spillway. The water can rise over the spillway crest, upto the maximum reservoir level, which can be estimated from the inflow flood hydrograph and the spillway characteristics, by the process of flood routing. Therefore, it is only the spillway, which will dispose of the surplus water and will not let the water rise above the maximum reservoir level. Had there been no such structure, over which the water would have overflown, the water level must have exceeded maximum reservoir level, and ultimately would have crossed the free board and thus over topped the darn, causing the failure of the dam. Hence, a spillway is essentially a safety valve for a dam. It must be properly designed and must have adequate capacity to dispose of the entire surplus water at the time of the arrival of" the worst design flood.

एक स्पिलवे एक बांध स्थल पर निर्मित संरचना है, जो अपस्ट्रीम से डाउनस्ट्रीम तक अधिशेष जल का प्रभावी ढंग से निपटता है। जलाशय भर जाने के बाद, सामान्य पूल स्तर तक, पानी स्पिलवे शिखर के ऊपर से बह जाता है (जो आम तौर पर सामान्य पूल स्तर पर रखा जाता है)। इन्फ्लो दर के आधार पर, पानी सामान्य पूल स्तर से ऊपर उठना शुरू कर देगा, और साथ ही, इसे स्पिलवे पर छोड़ दिया जाएगा। बाढ़ के मार्ग की प्रक्रिया के द्वारा, पानी का प्रवाह अधिकतम शिखर पर अधिकतम जलाशय स्तर तक बढ़ सकता है, जो प्रवाह की बाढ़ के जलग्राही और स्पिलवे विशेषताओं से अनुमान लगाया जा सकता है। इसलिए, यह केवल स्पिलवे है, जो अधिशेष जल का निपटान करेगा और अधिकतम जलाशय स्तर से ऊपर पानी बढ़ने नहीं देगा। अगर ऐसी कोई संरचना नहीं थी, जिस पर पानी बह निकला होता तो पानी का स्तर अधिकतम जलाशय स्तर से अधिक हो सकता था, और अंततः फ्रीबोर्ड को पार कर दिया जाता था और इसने रफू को धराशायी कर दिया, जिससे बांध की विफलता हो। इसलिए, एक स्पिलवे बांध के लिए एक सुरक्षा वाल्व है। यह ठीक से डिजाइन किया जाना चाहिए और "सबसे खराब डिजाइन बाढ़ के आगमन के समय पूरे अधिशेष जल के निपटान की पर्याप्त क्षमता होनी चाहिए।

Depending upon the type of the structure constructed for disposing of the surplus water, the Spiliways can be of the following major types :
(1) Straight Drop Spillway
(2) Overflow Spillway generally called Ogee Spillway
(3) Chute Spillway often called Trough Spillway or Open channel Spillway
(4) Side Channel Spillway
(5) Show Spillway
(6) Syphon Spillway


Straight Drop Spillway
This is the simplest type of spillway and may be constructed on small bunds or on thin arch dams, etc. It is a low weir and simple vertical fall type structure. as shown in figure.The downstream face of the structure may be kept vertical or slightly inclined. The crest is sometimes extended in the form of an overhanging tip, which keeps small discharges away from the face of the overfall section. The water falls freely from the crest under the action of gravity. Since vacuum gets created in the underside portion of the falling jet, sufficient ventilation of the nappe is acquired in order to avoid pulsating and fluctuating effects of the jet. Sometimes, a secondary dam of low height is constructed on the down stream side to create an artificial pool of water so as to dissipate the energy of the falling water.
(यह स्पिलवे का सबसे सरल प्रकार है और छोटे बांधों पर या पतले चाप बांधों पर आदि का निर्माण किया जा सकता है। यह कम कमर और सरल ऊर्ध्वाधर गिरती प्रकार संरचना है। जैसा कि आंकड़े में दिखाया गया है। ढांचे के नीचे की ओर के चेहरे को ऊर्ध्वाधर या थोड़ा झुकाव रखा जा सकता है। शिखर को कभी-कभी एक ओवरहांगिंग टिप के रूप में विस्तारित किया जाता है, जो छोटे से डिस्पैचों को अप्रभावित अनुभाग के चेहरे से दूर रखता है। गुरुत्वाकर्षण की कार्रवाई के तहत पानी गिरता है। चूंकि गिरने वाले जेट के निचले हिस्से में वैक्यूम बन जाता है, इसलिए जेट के स्पंदन और अस्थिर प्रभाव से बचने के लिए nappe के पर्याप्त वेंटिलेशन को हासिल किया जाता है। कभी-कभी, कम ऊंचाई का एक माध्यमिक बांध पानी के एक कृत्रिम पूल को बनाने के लिए नीचे की ओर की तरफ बांधता है ताकि गिरते पानी की ऊर्जा नष्ट हो सके।)

STRAIGHT DROP SPILLWAY

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