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. The exam will be conducted in the month of May 2018.
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. परीक्षा मई 2018 के महीने में आयोजित की जायेगी.
Q1. A fan produces feeling of comfort during hot weather, because-
एक पंखा गर्म मौसम के दौरान आराम की भावना पैदा करता है, क्योंकि -
(a) Fan supplies cold air/फैन ठंडी हवा की आपूर्ति करता है
(b) Our perspiration evaporates rapidly/आपका पसीना तेजी से सुखा देता है
(c) Our body radiates more heat/हमारे शरीर से अधिक गर्मी प्रसारित करता है
(d) Conductivity of air increase/वायु के प्रवाह में वृद्धि होती है
Ans.(b)
Sol. In summer, a ceiling fan in the counterclockwise direction can help to cool your home by pushing cool air down. During the hot summer months, though this wind chill effect can work to your advantage by providing a breeze that can help evaporate the skin’s moisture quickly, creating a cool feeling.
Sol. In summer, a ceiling fan in the counterclockwise direction can help to cool your home by pushing cool air down. During the hot summer months, though this wind chill effect can work to your advantage by providing a breeze that can help evaporate the skin’s moisture quickly, creating a cool feeling.
Q2. In an earthen pitcher, the water remains cold due to the process of
मिटटी के घड़े में,किस प्रक्रिया की वजह से पानी ठंडा रहता है?
(a) Condensation /संक्षेपण
(b) Evaporation /वाष्पीकरण
(c) Sublimation /उर्ध्वपातन
(d) None of the above /उपरोक्त में से कोई भी नहीं
Show Answer
Ans.(b)
Sol. The water remains cold in an earthen pitcher because of a physical process is known as evaporation, when liquid changes to a gaseous (or vapour) state without boiling, it is known as evaporation. The earthen pitcher is made of mud and has many minute pores. It is through these pores that the water, placed inside the pitcher, oozes out. Now to evaporate, the water needs to absorb heat, which will change it to vapour. The only way the water oozing out of the pitchers can turn to vapour is by absorbing heat from the liquid within the pot. Due to this process of continuous absorption of heat from water inside the pot, in a few hours, this water becomes cool.
Sol. The water remains cold in an earthen pitcher because of a physical process is known as evaporation, when liquid changes to a gaseous (or vapour) state without boiling, it is known as evaporation. The earthen pitcher is made of mud and has many minute pores. It is through these pores that the water, placed inside the pitcher, oozes out. Now to evaporate, the water needs to absorb heat, which will change it to vapour. The only way the water oozing out of the pitchers can turn to vapour is by absorbing heat from the liquid within the pot. Due to this process of continuous absorption of heat from water inside the pot, in a few hours, this water becomes cool.
Q3. In the season of summer, we experience a humid heat when weather:
गर्मी के मौसम में,किस दौरान हम एक आर्द्र गर्मी का अनुभव करते हैं:
(a) Start of summer / गर्मी की शुरुआत
(b) Middle of summer / गर्मी के मध्य
(c) high evaporation / उच्च वाष्पीकरण
(d) extreme temperature / चरम तापमान
Show Answer
Ans.(d)
Sol. In the season of summer, when the weather is humid, we experience humid heat.
Sol. In the season of summer, when the weather is humid, we experience humid heat.
Q4. Xeric condition refers to-
ज़ैरिक स्थिति का संदर्भ है
(a) low temperature/कम तापमान
(b) low humidity/कम नमी
(c) high evaporation/उच्च वाष्पीकरण
(d) extreme temperature/अधिकतम तापमान
Show Answer
Ans.(b)
Sol. Xeric condition refers to low humidity. It is a challenging place with poor sandy soil, the extreme condition of rain and drought. Xeric environment is place where water is meager.
Sol. Xeric condition refers to low humidity. It is a challenging place with poor sandy soil, the extreme condition of rain and drought. Xeric environment is place where water is meager.
Q5. Assertion (A) : The boiling point of water decreases as the altitude increases.
अभिकथन (A) :ऊंचाई बढ़ने के साथ पानी का क्वथनांक कम हो जाता है
Reason (R) : The atmospheric pressure increases with altitude.
कारण (R) : ऊंचाई के साथ वायुमंडलीय दबाव बढ़ता है
Code:
(a) Both (A) and (R) are true, and (R) is the correct explanation of (A)./दोनों (A) और (R) सत्य हैं, और (R), (A) का सही स्पष्टीकरण है.
(b) Both (A) and (R) are true, but (R) is not the correct explanation of (A)./दोनों (A) और (R) सत्य हैं, लेकिन (R), (A) का सही स्पष्टीकरण नहीं है.
(c) (A) is true, but (R) is false./(A) सत्य हैं, लेकिन (R) असत्य है.
(d) (A) is false, but (R) is true./(A) असत्य है, लेकिन (R) सत्य हैं
Show Answer
Ans.(c)
Sol. The atmospheric pressure decreases as one climbs higher in the atmosphere and increases closer to the earth’s surface. The boiling point of water decreases as the altitude increases. Thus, (A) is true but (R) is false.
Sol. The atmospheric pressure decreases as one climbs higher in the atmosphere and increases closer to the earth’s surface. The boiling point of water decreases as the altitude increases. Thus, (A) is true but (R) is false.
Q6. The atmosphere exerts enormous pressure on us. But, we do not feel it because
वायुमंडल हमारे ऊपर भारी दबाव डालता है, लेकिन, हम इसे महसूस नहीं करते हैं क्योंकि
(a) Our blood exerts a pressure slightly more than that of the atmosphere / हमारा रक्त वायुमंडल की तुलना में थोड़ा अधिक दबाव डालता है
(b) We are used to it / हम इसके आदी हो चुके है
(c) Our bones are very strong and can withstand the pressure / हमारी हड्डियां बहुत मजबूत हैं और दबाव का सामना कर सकती हैं
(d) The surface area of our head is very small / हमारे सिर का सतह क्षेत्र बहुत छोटा है
Show Answer
Ans.(a)
Sol. The atmosphere exerts enormous pressure on us but we do not feel it, because our blood exerts pressure slightly more than that of the atmosphere. We feel this pressure in water because the pressure underwater is greater than our normal blood pressure.
Sol. The atmosphere exerts enormous pressure on us but we do not feel it, because our blood exerts pressure slightly more than that of the atmosphere. We feel this pressure in water because the pressure underwater is greater than our normal blood pressure.
Q7. Assertion (A) : With the increase of temperature, the viscosity of glycerin increases.
अभिकथन (A) : तापमान की वृद्धि के साथ, ग्लिसरीन की चिपचिपाहट बढ़ जाती है.
Reason (R) : Rise of temperature increases kinetic energy of molecules./कारण (R) : तापमान बढ़ने के कारण अणुओं की गतिज ऊर्जा बढ़ जाती है.
Code/कोड:
(a) Both (A) and (R) are true, and (R) is the correct explanation of (A)./दोनों (A) और (R) सत्य हैं, और (R), (A) का सही स्पष्टीकरण है.
(b) Both (A) and (R) are true, but (R) is not the correct explanation of (A)./दोनों (A) और (R) सत्य हैं, लेकिन (R), (A) का सही स्पष्टीकरण नहीं है.
(c) (A) is true, but (R) is false./(A) सत्य हैं, लेकिन (R) असत्य है.
(d) (A) is false, but (R) is true./(A) असत्य है, लेकिन (R) सत्य हैं
Show Answer
Ans.(d)
Sol. The temperature dependence of liquid (Glycerin etc) viscosity is the phenomenon by which liquid viscosity tends to decrease as its temperature increases. The increases in temperature causes the kinetic or thermal energy to increase and the molecules become more movable.
Sol. The temperature dependence of liquid (Glycerin etc) viscosity is the phenomenon by which liquid viscosity tends to decrease as its temperature increases. The increases in temperature causes the kinetic or thermal energy to increase and the molecules become more movable.
Q8. Pressure-cooker cooks food in lesser time because
प्रेशर-कुकर में खाना पकाने में कम समय लगता है क्योंकि
(a) The temperature of boiling water decreases due to high pressure / उबलते पानी का तापमान उच्च दबाव के कारण घटता है
(b) Air has no effect as it is closed from all sides / वायु का कोई असर नहीं पड़ता क्योंकि यह सभी तरफ से बंद है
(c) Temperature of boiling water increases due to high pressure / उच्च दबाव के कारण उबलते पानी का तापमान बढ़ता है
(d) Evaporation of the water used is very small / पानी का वाष्पीकरण बहुत कम होता है
Show Answer
Ans.(c)
Sol. Food can be cooked faster in a pressure cooker since the boiling point of water increases with pressure. As the water boils, the steam produced cannot evaporate so the pressure inside the cooker increases. The boiling point of water now becomes 120°C. The load pin fixed on the heavy aluminum lid prevents any escape of steam. The rubber ring around the lid deals the liquid inside. Thus food gets cooked faster in a pressure cooker. Pressure cookers are more common in the mountains where elevation is high. At higher elevations, atmospheric pressure is lower and therefore water boils at lower temperature. In order to make up for that difference, people use pressure cookers.
Sol. Food can be cooked faster in a pressure cooker since the boiling point of water increases with pressure. As the water boils, the steam produced cannot evaporate so the pressure inside the cooker increases. The boiling point of water now becomes 120°C. The load pin fixed on the heavy aluminum lid prevents any escape of steam. The rubber ring around the lid deals the liquid inside. Thus food gets cooked faster in a pressure cooker. Pressure cookers are more common in the mountains where elevation is high. At higher elevations, atmospheric pressure is lower and therefore water boils at lower temperature. In order to make up for that difference, people use pressure cookers.
Q9. When a bottle is filled with water and it is freezing the bottle breaks down, because-
जब एक पानी से भरी बोतल को ठंडा किया जाता है तो बोतल टूट जाती है क्यूंकि-
(a) Water expands upon freezing / पानी ठंडा करने पर फैलता है
(b) Bottles shrinks at freezing point / बोतले हिमांक बिन्दू पर सिकुड़ती है
(c) The temperature outside the bottle is higher than inside / बोतल के बाहर का तापमान अंदर से अधिक है
(d) Water expands on heating / पानी गर्म करने पर फैलता है
Show Answer
Ans.(a)
Sol. A glass bottle containing water breaks when kept in a freezer because the frozen water will have more volume than the liquid water. So increased volume will put pressure on the walls of the bottle and it will break.
Sol. A glass bottle containing water breaks when kept in a freezer because the frozen water will have more volume than the liquid water. So increased volume will put pressure on the walls of the bottle and it will break.
Q10. A glass bottle containing water tightly corked breaks when if is kept in freezer, because-
पानी की एक कांच की बोतल को जब फ्रीजर में रखा जाता है तो यह कास जाती है, क्यूंकि-
(a) Bottle shrinks on freezing / बोतल ठंडा करने पर सिकुड़ती है
(b) The volume of water decreases on freezing / ठंडा करने पर पानी की मात्रा घट जाती है
(c) The volume of water increases on freezing/ ठंडा करने पर पानी की मात्रा बढ़ जाती है
(d) Glass is the bad conductor of heat / ग्लास ऊष्मा का कुचालक है
Show Answer
Ans.(c)
Sol. A glass bottle containing water breaks when kept in a freezer because the frozen water will have more volume than the liquid water. So increased volume will put pressure on the walls of the bottle and it will break.
Sol. A glass bottle containing water breaks when kept in a freezer because the frozen water will have more volume than the liquid water. So increased volume will put pressure on the walls of the bottle and it will break.
Q11. Cloudy nights are warmer compared to clear cloudless nights, because clouds-
बादलों वाली रात बिना बादलों की रात तुलना में अधिक गर्म होती है, क्यूंकि बादल
(a) Prevent cold waves from the sky from descending on earth/ ठंडी हवाओं को पृथ्वी पर आने से रोकते है
(b) Reflect back the heat given off by earth / पृथ्वी से दी गई गर्मी को वापस प्रतिबिंबित करता है
(c) Produce heat and radiate it towards earth / गर्मी का उत्पादन करता है और इसे पृथ्वी की ओर विकिरित करता है
(d) Absorb heat from the atmosphere and send it toward earth. / वातावरण से गर्मी को अवशोषित करता है और इसे पृथ्वी की ओर भेजता है
Show Answer
Ans.(b)
Sol. When you have cloudy night, the clouds prevent heat from escaping through the atmosphere and into space. The clouds act like a blanket and trap the heat. That is why every time there is a cloudy night, it is always warmer than a clear night.
Sol. When you have cloudy night, the clouds prevent heat from escaping through the atmosphere and into space. The clouds act like a blanket and trap the heat. That is why every time there is a cloudy night, it is always warmer than a clear night.
Q12. Fruit stored in a cold chamber exhibit longer storage life because-
ठंडे कक्ष में संग्रहीत फल लंबे भंडारण जीवन को प्रदर्शित करता है क्योंकि
(a) Exposure to sunlight is prevented / सूरज की रोशनी के लिए अनावरण रोका जाता है
(b) Concentration of carbon dioxide in environment is increases / वातावरण में कार्बन डाइऑक्साइड की एकाग्रता बढ़ जाती है
(c) Rate of respiration is decreased / श्वसन की दर में कमी आई है
(d) There is increase in humidity / आर्द्रता में वृद्धि होती है
Show Answer
Ans.(c)
Sol. It is well known that even after harvesting of the fruits the process of respiration continues and brings about ripening, change in colour, softening of flesh, increase in sugar content and development of flavour. These changes occur more rapidly at higher temperature. This means that the lower the temperature of storage the longer would be the storage life of the fruit. In cold storages the rate of respiration of fruits is decreased.
Sol. It is well known that even after harvesting of the fruits the process of respiration continues and brings about ripening, change in colour, softening of flesh, increase in sugar content and development of flavour. These changes occur more rapidly at higher temperature. This means that the lower the temperature of storage the longer would be the storage life of the fruit. In cold storages the rate of respiration of fruits is decreased.
Q13. A hydrogen-inflated polythene balloon is released from the surface of the earth. As the balloon rises to an altitude up in the atmosphere, it will-
एक हाइड्रोजन-युक्त पॉलीथीन गुब्बारा पृथ्वी की सतह से छोड़ा जाता है, जैसे जैसे गुब्बारा वातावरण में ऊंचाई तक बढ़ता है, यह
(a) Decrease in size / आकार में कम होता है
(b) Flatten into disc-like shape / डिस्क के आकार में चपटा हो जाता है
(c) Increase in size / आकार में बढ़ जाता है
(d) Maintain the same size and shape / समान आकार और आकार बनाए रखें
एक हाइड्रोजन-युक्त पॉलीथीन गुब्बारा पृथ्वी की सतह से छोड़ा जाता है, जैसे जैसे गुब्बारा वातावरण में ऊंचाई तक बढ़ता है, यह
(a) Decrease in size / आकार में कम होता है
(b) Flatten into disc-like shape / डिस्क के आकार में चपटा हो जाता है
(c) Increase in size / आकार में बढ़ जाता है
(d) Maintain the same size and shape / समान आकार और आकार बनाए रखें
Show Answer
Ans.(c)
Sol. If a hydrogen-inflated polythene balloon is released from the surface of the earth, then the air pressure at high altitude is reduced. Thus, the balloon will expand until the pressure inside the balloon equals the pressure outside.
Sol. If a hydrogen-inflated polythene balloon is released from the surface of the earth, then the air pressure at high altitude is reduced. Thus, the balloon will expand until the pressure inside the balloon equals the pressure outside.
Q14. Assertion (A) : Woollen clothes keeps us warm.
अभिकथन (A):ऊनी कपड़े हमें गर्म रखता है
Reason (R) : Woollen fibres are made from a special type of protein, which is a bad conductor of heat
कारण (R) : ऊनी फाइबर एक विशेष प्रकार के प्रोटीन से बने होते हैं, जो गर्मी का एक कुचालक है
Select the correct answer from the codes given below/ नीचे दिए गए कोड से सही उत्तर का चयन करें:
(a) Both (A) and (R) are true, and (R) is the correct explanation of (A)./दोनों (A) और (R) सत्य हैं, और (R), (A) का सही स्पष्टीकरण है.
(b) Both (A) and (R) are true, but (R) is not the correct explanation of (A)./दोनों (A) और (R) सत्य हैं, लेकिन (R), (A) का सही स्पष्टीकरण नहीं है.
(c) (A) is true, but (R) is false./(A) सत्य हैं, लेकिन (R) असत्य है.
(d) (A) is false, but (R) is true./(A) असत्य है, लेकिन (R) सत्य हैं
Show Answer
Ans.(c)
Sol. Woollen clothes keep us warm in winter. It is just because woolen clothes have fibres and between those fibres, air is trapped which reduces heat loss. Air reduces heat loss because it is an insulator or poor conductor of heat. Thus statement (A) is correct but reason (R) is false.
Sol. Woollen clothes keep us warm in winter. It is just because woolen clothes have fibres and between those fibres, air is trapped which reduces heat loss. Air reduces heat loss because it is an insulator or poor conductor of heat. Thus statement (A) is correct but reason (R) is false.
Q15. Which one of the following statements is not correct?
निम्नलिखित में से कौन सा कथन सही नहीं है?
(a) The velocity of sound in air increases with the increase of temperature / तापमान में वृद्धि के साथ हवा में ध्वनि की गति बढ़ जाती है
(b) The velocity of sound in air is independent of pressure / हवा में ध्वनि की गति दबाव से स्वतंत्र है
(c) The velocity of sound in air decreases as the humidity increases / नमी बढ़ने के कारण हवा में ध्वनि की गति कम हो जाती है
(d) The velocity of sound in air is not affected by the change in amplitude and frequency / हवा में ध्वनि की गति आयाम और आवृत्ति में परिवर्तन से प्रभावित नहीं होती है
Show Answer
Ans.(c)
Sol. Humidity is the percentage of water vapour present in air. As the humidity increases, the percentage of water vapour in air increase and this decreases the density of air. This results in the increase of velocity of sound. So increase in the humidity of air increases the velocity of sound in air. Thus, statement (c) is not correct.
Sol. Humidity is the percentage of water vapour present in air. As the humidity increases, the percentage of water vapour in air increase and this decreases the density of air. This results in the increase of velocity of sound. So increase in the humidity of air increases the velocity of sound in air. Thus, statement (c) is not correct.
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