Railway Board offers opulent and revered job posts to its aspirants. And it is not every year that we get the notification from Railway offering a good number of vacant seats to the multitude aspirants. But the current year 2018 brought a pleasant surprise with almost 90,000 seats to be filled by the valid candidates. Opportunity is here but you have to welcome it with a provident strategy.
रेलवे बोर्ड अपने उम्मीदवारों के लिए भव्य और प्रतिष्ठित कार्य पदों की पेशकश करता है. और हर साल ऐसा नहीं होता है कि हमें रेलवे की ओर से अधिसूचना मिलती है. लेकिन वर्तमान वर्ष 2018 आपके लिए बहुत सुखद वर्ष है क्योंकि इसमें लगभग 90,000 सीटों को वैध उम्मीदवारों द्वारा भरा जाएगा. आपके पास बहुत अच्छा अवसर है और आपको इसे एक बेहतर रणनीति से प्राप्त करना होगा.
Q1. Which one of the following liquids is very good conductor of heat?
निम्न में से कौन सा तरल ऊष्मा का सबसे अच्छा सुचालक है?
(a) Mercury /पारा
(b) Water / पानी
(c) Ether / ईथर
(d) Benzene/ बेंजीन
Ans.(a)
Sol. Mercury is a chemical element with the symbol (Hg). Mercury is used in thermometers due to its special properties. It can measure a wide range of temperatures from – 40 to 356°C and up to 570°C under pressure in a liquid state. It expands changes. A heavy, silvery d-block element, mercury is the only metallic element which is found in liquid state at standard conditions for temperature and pressure.
Sol. Mercury is a chemical element with the symbol (Hg). Mercury is used in thermometers due to its special properties. It can measure a wide range of temperatures from – 40 to 356°C and up to 570°C under pressure in a liquid state. It expands changes. A heavy, silvery d-block element, mercury is the only metallic element which is found in liquid state at standard conditions for temperature and pressure.
Q2. Which one of the following metals is liquid at ordinary temperature?
निम्नलिखित धातुओं में से कौन सी धातु सामान्य तापमान पर तरल है?
(a) Lead / लेड
(b) Nickel/ निकेल
(c) Mercury /पारा
(d) Tin / टिन
Show Answer
Ans.(c)
Sol. Mercury is the only common metal which is liquid at ordinary temperature. Mercury is sometimes called quicksilver.
Sol. Mercury is the only common metal which is liquid at ordinary temperature. Mercury is sometimes called quicksilver.
Q3. Mercury is basically used in thermometer devices because its epeciality is
पारा मूल रूप से थर्मामीटर उपकरणों में उपयोग किया जाता है क्योंकि इसकी विशिष्टता है-
(a) High density/ उच्च घनत्व
(b) High liquidity/ उच्च तरलता
(c) Good conductor of heat/ ऊष्मा के अच्छे सुचालक
(d) High specific heat/ उच्च विशिष्ट गर्मी
Show Answer
Ans.(c)
Sol. Mercury is easily the best liquid to use in thermometers, five important reasons are -
Sol. Mercury is easily the best liquid to use in thermometers, five important reasons are -
- It is very reflective, so it’s easy to see and to read accurately.
- It doesn’t wet the glass, so you don’t get an inaccurate reading if the temperature is falling.
- It is metal, so it’s good conductor of heat.
- It expands evenly with the temperature so a linear scale can be used with a high degree of accuracy.
- there is a large of range of temperature for which it is a liquid
Q4. There is no reaction when steam passes over
भाप के _____ के ऊपर से गुजरने पर कोई प्रतिक्रिया नहीं होती है.
(a) Aluminium/ एल्यूमिनियम
(b) Copper/ तांबा
(c) Carbon/ कार्बन
(d) Iron/ आयरन
Show Answer
Q5. Iron is obtained from
आयरन से प्राप्त किया जाता है-
(a) Limestone/ चूना पत्थर
(b) pitch-blende/ पिचब्लेंड
(c) Monazite sand/ मोनजाइट रेत
(d) Hematite/ हेमेटाइट
Q6. Easily soluble in water-
पानी में आसानी से घुलनशील है-
(a) Carbon/कार्बन
(b) Nitrogen/नाइट्रोजन
(c) Ammonia/अमोनिया
(d) Iodine/आयोडीन
Ans.(a)
Sol. There is no reaction when steam passes over aluminium.
Sol. There is no reaction when steam passes over aluminium.
Q5. Iron is obtained from
आयरन से प्राप्त किया जाता है-
(a) Limestone/ चूना पत्थर
(b) pitch-blende/ पिचब्लेंड
(c) Monazite sand/ मोनजाइट रेत
(d) Hematite/ हेमेटाइट
Show Answer
Ans.(d)
Sol. Iron ores are rocks and minerals from which metallic iron can be economically extracted. The ores are usually rich in iron oxides and the iron itself is usually found in the form of magnetite (Fe3O4 – 72.4% Fe), hematite (Fe2O3 – 69.9% Fe).
Sol. Iron ores are rocks and minerals from which metallic iron can be economically extracted. The ores are usually rich in iron oxides and the iron itself is usually found in the form of magnetite (Fe3O4 – 72.4% Fe), hematite (Fe2O3 – 69.9% Fe).
Q6. Easily soluble in water-
पानी में आसानी से घुलनशील है-
(a) Carbon/कार्बन
(b) Nitrogen/नाइट्रोजन
(c) Ammonia/अमोनिया
(d) Iodine/आयोडीन
Show Answer
Ans. (c)
Sol. Ammonia being a polar molecule dissolves readily in water. This is due to the Hydrogen atoms of Ammonia which are bonded with a highly electronegative Nitrogen and the Hydrogen atoms of water molecules which are bonded with the highly electronegative Oxygen atom.
Sol. Ammonia being a polar molecule dissolves readily in water. This is due to the Hydrogen atoms of Ammonia which are bonded with a highly electronegative Nitrogen and the Hydrogen atoms of water molecules which are bonded with the highly electronegative Oxygen atom.
हास्य गैस (लाफिंग गैस) के रूप में उपयोग की जाने वाली गैस है-
(a) Nitrous Oxide / नाईट्रस ऑक्साइड
(b) Nitrogen dioxide / नाइट्रोजन डाइऑक्साइड
(c) Nitrogen Trioxide / नाइट्रोजन ट्रायऑक्साइड
(d) Nitrogen Tetra Oxide / नाइट्रोजन टेट्राऑक्साइड
Show Answer
Ans.(a)
Sol. Nitrous Oxide (N_2 O) is also known as laughing gas. It is a colourless gas with a sweet odour and taste. Inhalation leads to disorientation, euphoria, numbness, loss of coordination, dizziness and ultimately a loss of consciousness. It is also used as the anesthetic gas.
निम्नलिखित में से किसे स्ट्रेंजर गैस भी कहा जाता है?
(a) Argon / आर्गन
(b) Neon / नीओन
(c) Xenon / क्सीनन
(d) Nitrous Oxide / नाइट्रस ऑक्साइड
Show Answer
Ans.(c)
Sol. Xenon is a chemical gas with symbol Xe and atomic number 54. It is a rare, odourless, colourless, tasteless, chemically unreactive gas. Xenon gas is also known as stranger gas as its volume is low in the atmosphere (0.08 parts per million of xenon). It was discovered in England by the Scottish chemist William Ramsay and British chemist Morris Travers in 1898.
एक विमान के टायर में हवा भरने के लिए कौन सी गैस का प्रयोग किया जाता है?
(a) Hydrogen / हाइड्रोजन
(b) Nitrogen / नाइट्रोजन
(c) Helium /हीलियम
(d) Neon / नीयन
Show Answer
Ans.(b)
Sol. Nitrogen gas is used in the types of an aeroplane. This is because the nitrogen gas does not support combustion and can assist in preventing wheel fire when the aircraft lands (braking and high speed can produce dangerously high temperatures) unlike in oxygen. There are other benefits but effectively it is being the lowest cost gas that does not support combustion. It is preferred in comparison with the oxygen because nitrogen does not contain water. Thus, when the plane is at more height, gas in tyres does not get frozen.
निम्नलिखित में से कौन सी एक मिश्र धातु नहीं है?
(a) Steel / स्टील
(b) Brass / पीतल
(c) Bronze / कांस्य
(d) Copper / कॉपर
Show Answer
Ans.(d)
Sol. Copper is a metal, however steel, brass and bronze are alloys.
Sol. Copper is a metal, however steel, brass and bronze are alloys.
निम्नलिखित में से कौन सा सफेद फास्फोरस है?
(a) P1
(b) P6
(c) P4
(d) P5
Show Answer
Ans.(c)
Sol. The most important form of elemental phosphorus from the perspective of applications and chemical literature is white phosphorus. It consists of tetrahedral P4molecules, in which each atom is bound to the other three atoms by a single bond.
Q12. Permanent hardness of water is due to-
पानी की स्थायी कठोरता की वजह है:
(a) Chlorides and sulphates of Calcium and Magnesium / कैल्शियम और मैग्नेशियम के क्लोराइड और सल्फाट
(b) Calcium bicarbonate sulphates / कैल्शियम बिकारबोनेट सल्फ़ेट्स
(c) Magnesium bicarbonate / मैग्नेशियम बाइकार्बोनेट
(d) Clorides of Silver and Potassium / सिल्वर और पोटेशियम के क्लोराइड्स
पानी की स्थायी कठोरता की वजह है:
(a) Chlorides and sulphates of Calcium and Magnesium / कैल्शियम और मैग्नेशियम के क्लोराइड और सल्फाट
(b) Calcium bicarbonate sulphates / कैल्शियम बिकारबोनेट सल्फ़ेट्स
(c) Magnesium bicarbonate / मैग्नेशियम बाइकार्बोनेट
(d) Clorides of Silver and Potassium / सिल्वर और पोटेशियम के क्लोराइड्स
Show Answer
Ans.(a)
Permanent hardness in water is hardness due to the presence of the chlorides and sulphates of calcium and magnesium,
Q13.The pH-value for water is-
पानी का pH-मान है -
(a) Nearly zero / लगभग शून्य
(b) 7/ 7
(c) 5 or less than 5 /5 या 5 से कम
(d) 8.7 or more / 8.7 या अधिक
पानी का pH-मान है -
(a) Nearly zero / लगभग शून्य
(b) 7/ 7
(c) 5 or less than 5 /5 या 5 से कम
(d) 8.7 or more / 8.7 या अधिक
Show Answer
Ans.(b)
Sol. The pH value of pure water is 7. Pure water is neutral by nature. The solution with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline.
पानी आयनिक लवण का एक अच्छा विलायक है क्योंकि-
(a) It has a high boiling point / इसका उच्च क्वथनांक है
(b) It has a high dipole moment / इसमें एक उच्च द्विध्रुव आघूर्ण है
(c) It has a high specific heat / इसमें उच्च विशिष्ट ताप है
(d) It has no colour / इसका कोई रंग नहीं है
Show Answer
Ans.(b)
Sol. Water is a good solvent due to its polarity which can easily dissolve into polar compounds. Water dissolves ionic salts by hydrating their component ions. For example, water dissolves NaCl by hydrating and stabling the Na+ and Cl– ions.
अशुद्ध पानी से पीने के पानी की बड़ी मात्रा को किसके द्वारा तैयार किया जाता है -
(a) Desalination / विलवणीकरण
(b) Distillation / आसवन
(c) Ion-exchange / आयन विनिमय
(d) Decantation / निस्तारण
Show Answer
Ans.(a)
Sol. Desalination is a process that removes minerals from saline water (Also refer to removal of salts and minerals). Seawater desalination has a very effective way of production of potable water for drinking and industries.
Sol. Desalination is a process that removes minerals from saline water (Also refer to removal of salts and minerals). Seawater desalination has a very effective way of production of potable water for drinking and industries.
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