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 1,20,000 seats to be filled by the valid candidates. Opportunity is here but you have to welcome it with a provident strategy.
Q1. The temperature is measured with
तापमान किसके द्वारा मापा जाता है
(a)Altimeter/अल्टीमीटर
(b) Pyrometer / पाइरोमीटर
(c) Ammeter/ एम्मिटर
(d) Callipers/ कैलिपरस
Sol. Pyrometer is an instrument for measuring high temperatures, especially in furnaces and kilns.
Q2. Photovoltaic cells are ?
फोटोवोल्टाइक सेल क्या हैं
(a) Solar cells / सौर सेल
(b) Thermal cells / तापीय सेल
(c) Sulphur cells / सल्फर सेल
(d) Molar cells/ मोलर सेल
Sol. The conversion of light energy into electrical energy is based on the phenomenon called photovoltaic effect. A photovoltaic cell is the basic unit of the system where the photovoltaic effect is utilized to produce electricity from light energy. Silicon is most widely used semiconductor material for construction photovoltaic cell.
Q3. When the door of refrigerator is opened in a closed room, then:
जब एक बंद कमरे में फ्रिज का दरवाजा खोला जाता है, तो:
(a) Immediately room become cooler/ अचानक कमरा ठंडा हो जाता है
(b) the temperature of room falls gradually/ कमरे का तापमान धीरे-धीरे गिरता है
(c) the temperature of room is not affected / कमरे का तापमान प्रभावित नहीं होता
(d) the room becomes hotter gradually/ कमरा धीरे-धीरे गर्म हो जाता है
Sol. The reason is that with the door open the temperature will start to rise inside the refrigerator. The thermostat will kick in and try to cool it back down. This means the motor is running which means heat is being added to the room.
Q4. Why does food cook faster in a pressure cooker?
प्रेशर कुकर में खाना जल्दी पकाया जा सकता है ऐसा क्यों –
(a) The increased pressure increases the boiling point. / बढ़ता दबाव उबलते बिंदु को बढ़ाता है
(b) Does not waste steam. / भाप बर्बाद नहीं करता है
(c) The food is cooked quickly by steam. / भोजन भाप द्वारा जल्दी पकता है
(d) The water boils at constant temperature. / पानी लगातार एक ही तापमान पर उबलता है.
Sol. The trapped steam increases the atmospheric pressure inside the cooker by 15 pounds per square inch (psi), or 15 pounds above normal sea-level pressure. At that pressure, the boiling point of water is increased from 212°F to 250°F. This higher temperature cooks food faster.
Q5. A body floats at 4°C water. If temperature reaches 100°C then-
शरीर 4 डिग्री सेल्सियस पानी में तैरता है। यदि तापमान 100 डिग्री सेल्सियस तक पहुंच जाता है तो-
(a) The body will sink/शरीर डूब जाएगा
(b) No change/कोई परिवर्तन नहीं होगा
(c) Some part of the body will submerge/शरीर का कुछ हिस्सा डूब जाएगा
(d) The body will float freely/शरीर स्वतंत्र रूप से तैरेगा
Sol. When the water is heated, its density decreases. The density of the water at 100°C is at the lowest, so the body will sink. Water density is maximum at 4°C, so the body will float.
Q6. Pure water freezes at what temperature?
शुद्ध पानी किस तापमान पर जम जाता है?
(a) 47 F
(b) 32 F
(c) 0 F
(d) 19 F
Sol. Water freezes at 32 degrees Fahrenheit, 0 degrees Celsius, 273.15 Kelvin.
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
Sol. Xeric condition refers to low humidity. Xeric environment is place where water is meager.
गुप्त ऊष्मा की S.I इकाई क्या है-
(a) cal-g
(b) cal/°C
(c) joule /kg- जूल/किग्रा
(d) none of these/इनमे से कोई नहीं
Sol. The SI unit of latent heat is joule per kilogram
न्यूनतम 40 डिग्री सेंटीग्रेड __ डिग्री फ़ारेनहाइट के बराबर है.
(a) 104
(b) 122
(c) – 40
(d) None of these/इनमे से कोई नहीं
Sol. Minus 40 degree centigrade is equal to -40 degree Fahrenheit.
Q10. The safest temperature for keeping food fresh in a refrigerator is
एक रेफ्रिजरेटर में खाना ताजा रखने के लिए सबसे सुरक्षित तापमान कितना है
(a) 4°C
(b) 8°C
(c) 0°C
(d) 10°C
Sol. Refrigerator temperatures do not destroy pathogenic or spoilage microorganisms. The lower temperature slows the growth of microorganisms already in the food. According to international standards, the recommended temperature of the refrigerator is 36°F to 38°F (1.7°C to 3.3°C). Thus option (a) is correct.
ब्रह्मांड के विस्तार की अवधारणा किस पर आधारित है –
(a) Doppler effect/डॉपलर प्रभाव
(b) Stark effect/बिल्कुल प्रभाव
(c) Zeeman effect/जीमन प्रभाव
(d) Raman effect/रमन प्रभाव
Sol. The concept of expanding universe is based on Doppler effect. It was named after Christian Doppler, who first came up with the idea in 1942. Edwin Hubble used the Doppler Effect to determine that universe is expanding. Hubble found that the light from distant galaxies was shifted towards lower frequencies, to the red end of the spectrum. This is known as a red Doppler shift or a red-shift.
एक बायोटेक्निक जिसमें अल्ट्रासोनिक ध्वनि का उपयोग किया जाता है –
(a) Sonography/ सोनोग्राफी
(b) E.C.G / ई.सी.जी
(c) E.E.G / ई.ई.जी.
(d) X-ray/एक्स-रे
Sol. Sonography or ultrasonography is an important mean of clinical diagnosis. It is a diagnostic imaging technique based on the application of ultrasound. It is widely used in the field of medical science.
Q13. CT Scan is done by using-
CT स्कैन किसका उपयोग करके किया जाता है –
(a) Infra-red Rays/अवरक्त किरणों
(b) Ultrasonic Waves/अल्ट्रासोनिक किरणों
(c) Visible Light/ दृश्य प्रकाश
(d) X-Rays / एक्स-रे
Sol. CT scan or computed tomography are special x-rays tests that produce cross-sectional images of the body using x-rays and a computer.
फाइबर ऑप्टिक्स संचार में, सिग्नल किसके रूप में यात्रा करता है –
(a) Lightwave / प्रकाश तरंग
(b) Radio wave/ रेडियो तरंग
(c) Microwave/ माइक्रो तंरग
(d) Electric wave /विद्युत तरंग
Sol. Fiber-optic communication is a method of transmitting information from one place to another by sending pulses of light through an optical fibre .
तापमान के बढ़ने के साथ, गैस में ध्वनि की गति में क्या परिवर्तन आता है ?
(a)increase / वृद्धि होती है
(b)decreases / घटता है
(c)remains the same / वही रहता है
(d)None of these / इनमें कोई नहीं
Sol. Molecules at higher temperatures have more energy, thus they can vibrate faster. Since the molecules vibrate faster, sound waves can travel more quickly. The speed of sound in room temperature air is 346 meters per second.
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