RRB JE : Science Quiz | 20th April

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. Railway JE is a great opportunity for all aspirants with a total of 13,487 vacancies and science is an important subject of the same. Here we are providing the science quiz to help our aspirants ace this subject.

Q1. The gas used in discharge tubes for optical decoration and advertising is-
ऑप्टिकल सजावट और विज्ञापन के लिए डिस्चार्ज ट्यूब में किस गैस का उपयोग किया जाता है?
(a) Carbon dioxide / कार्बन डाइऑक्साइड
(b) Ammonia / अमोनिया
(c) Sulphur dioxide / सल्फर डाइऑक्साइड
(d) Neon / नियॉन
Ans.(d)
Sol. The neon gas is used in discharge lamps, tubes and in fluorescent bulbs.

Q2. The formation of glittering colours in thin foam of soap is the result of which of the following phenomenon-
साबुन के पतले फोम में चमकदार रंगों का निर्माण निम्न में से किस घटना का परिणाम है?
(a) Reflection and interference / परावर्तन और व्यतिकरण
(b) Total refraction and dispersion / पूर्ण अपवर्तन और विसरण
(c) Diffraction and dispersion / विवर्तन एवं विसरण
(d) Polarization and interference/ ध्रुवीकरण और व्यतिकरण
Ans.(a)
Sol. A soap bubble is a very thin sheet of water sandwiched between two layers of soap molecules. Light is reflected from both the inner and outer surface of the soap bubble. The resulting colors are a combination of the colors that do not undergo destructive interference and their degrees of constructive interference. Blue-green colors dominate in thicker films and yellow hues in thinner films.

Q3. Total internal reflection can take place when light travels from:
जब प्रकाश ____ में गमन करता है तो पूर्ण आंतरिक परावर्तन हो सकता है।
(a) Diamond to glass/ हीरा से कांच
(b) Water to glass / पानी से कांच
(c) Air to water/ वायु से पानी
(d) Air to glass / वायु से कांच
Ans.(a)
Sol. Total internal reflection takes place when a ray of light is travelling from denser to thinner medium and angle of incidence is greater than the critical angle, the ray is completely reflected from the surface and meet each other as if the surface is a mirror. So according to options, the situation of option (a) is correct where total internal reflection takes place, it is because diamond is denser than glass.

Q4. Optical fibre works on the principle of:
ऑप्टिकल फाइबर किस सिद्धांत पर कार्य करता है?
(a) Total internal reflection / पूर्ण आंतरिक प्रतिबिंब
(b) Refraction / अपवर्तन
(c) Scattering / प्रकीर्णन
(d) Interference / व्यतिकरण
Ans.(a)
Sol. The optical fibre is a very him strand of glass or plastic cable for transmitting light from one point to another. They work on the principle of total internal reflection. There is no loss of signal through an optical fibre.

Q5. Who is the discoverer of Penicillin?
पेनिसिलिन के खोजकर्ता कौन हैं?
(a) Alexander Graham Bell/ अलेक्जेंडर ग्राहम बेल
(b) Alexander Fleming/ अलेक्जेंडर फ्लेमिंग
(c) Christopher Macdonald/ क्रिस्टोफर मैकडोनाल्ड
(d) Albert Einstein/ अल्बर्ट आइंस्टीन
Ans.(b)
Sol. Penicillin was discovered by Scottish scientist Alexander Fleming.

Q6. Dolphins are classified in-
डॉल्फ़िन को किस श्रेणी में वर्गीकृत किया गया है?
(a) Fish / मछली
(b) Amphibians/ उभयचर
(c) Reptile / सरीसृप
(d) Mammals / स्तनधारी
Ans.(d)
Sol. Dolphins are highly intelligent marine mammals and are part of the family of toothed whales. They are found worldwide, mostly in shallow seas of the continental shelves and are carnivores, mostly eating fish and squid. India has declared Ganga Dolphin as the national aquatic animal of India.

Q7. Amphibia are-
उभयचर हैं-
(a) Very fastly moving boats / बहुत तेज चलने वाली नावें
(b) Animals living in water only / केवल पानी में रहने वाले जंतु
(c) Animals living on land only / केवल भूमि पर रहने वाले जंतु
(d) Animals living equally in water and on land both/ जल और थल दोनों पर समान रूप से रहने वाले जंतु
Ans.(d)
Sol. The word “amphibian” is derived from the ancient Greek term amphibious, which means “both kinds of life”. The term was initially used as a general adjective for animals that could live on land or in water. They are ectotherms or cold-blooded animals, means they are unable to regulate their own body temperature.

Q8. Nilgai belongs to the following family:
नीलगाय निम्नलिखित में से किस परिवार से सम्बंधित है:
(a) Cow / गाय
(b) Goat/ बकरी
(c) Sheep / भेड़
(d) Deer / हिरण
Ans.(d)
Sol. Nilgai is the largest Asian antelope species. Antelope are creatures, who has strong permanent horns. There are more than 90 species of antelope.

Q9. Vitamin B-9 is also called ?
विटामिन B-9 को ___ भी कहा जाता है।
(a) Folic Acid/ फोलिक एसिड
(b) Citric Acid/ साइट्रिक एसिड
(c)Hydrochloric Acid/ हाइड्रोक्लोरिक अम्ल
(d) Biotin/ बायोटिन
Ans.(a)
Sol. Vitamin B9 – otherwise known as Folate (naturally occurring in foods) or Folic Acid (a synthetic folate compound used in vitamin supplements because of its increased stability). The name comes from ‘folium’, which is the Latin word for leaves, because folates were first isolated from spinach.

Q10. Which of following is synthesized by intestinal bacteria?
निम्नलिखित में से कौन आंतों के बैक्टीरिया द्वारा संश्लेषित होता है?
(a) Vitamin B_12 / विटामिन B12
(b) Vitamin C / विटामिन C
(c) Vitamin K / विटामिन K
(d) Vitamin B_12 and Vitamin K both/ विटामिन B12 और विटामिन K दोनों
Ans.(d)
Sol. Vitamin B_12 and vitamin K both are synthesized by bacteria in human intestine.

Q11. The most commonly used substance in fluorescent tubes are-
फ्लोरोसेंट ट्यूबों में सबसे अधिक इस्तेमाल किया जाने वाले पदार्थ हैं-
(a) Sodium Oxide and Argon / सोडियम ऑक्साइड और आर्गन
(b) Sodium Vapour and Neon / सोडियम वाष्प और नियॉन
(c) Mercury Vapour and Argon / पारा वाष्प और आर्गन
(d) Mercuric Oxide and Neon / मरक्यूरिक ऑक्साइड और नियॉन
Ans.(c)
Sol. Fluorescent lamp tube is filled with a gas containing low pressure mercury vapour and Argon. Sometimes gases like Xenon, Neon or Krypton can also be used. The pressure inside the lamp is around 0.3% of atmospheric pressure.

Q12. Which one of the following metals is accessed in the native state?
निम्नलिखित में से किस धातु को प्राकृतिक अवस्था में प्राप्त किया जा सकता है?
(a) Aluminium / एल्युमिनियम
(b) Gold / सोना
(c) Chromium / क्रोमियम
(d) Zinc / जिंक
Ans.(b)
Sol. Among the metals, gold is the least reactive, so this was accessed the in the native (free) state. On the basis of reactivity, the decreasing order (From top to bottom) of metals is given below. Lithium (Li), Potassium (K), Barium (Ba), Strontium (Sr), Calcium (Ca), Sodium (Na), Magnesium (Mg), Aluminium (Al), Manganese (Mn), Zinc (Zn), Chromium (Cr), Iron (Fe), Cadmium (Cd), Cobalt (Co), Nickel (Ni), Tin (Sn), Lead (Pb), Copper (Cu), Mercury (Hg), Silver (Ag), Platinum (Pt), Gold (Au).

Q13. Which gas is not in the gaseous cycle?
गैसीय चक्र में कौन सी गैस नहीं होती है?
(a) N_2
(b) O_2
(c) Carbon
(d) H_2
Ans.(d)
Sol. Biogeochemical cycles can be classed as gaseous in which the reservoir is that air or the oceans (via evaporation) and sedimentary in which the reservoir is earth’s crust. Gaseous cycles include Nitrogen, Oxygen, Carbon and Water. Sedimentary cycles include Iron, Calcium, Phosphorus, Sulphur and other more earthbound elements.

Q14. Of how many carats is the pure gold?
शुद्ध सोना कितने कैरेट का होता है?
(a) 22
(b) 24
(c) 28
(d) 20
Ans.(b)
Sol. It is an extension of the older carat (Karat in North American spelling) system of denoting the purity of gold by fractions of 24, such as ’18 carat’ for an alloy with 75% (18 parts per 24) pure gold, it is usually alloyed with base metals for use in jewellery, altering its hardness and ductility, melting point, colour and other properties. Alloys with lower carat rating typically 22k, 18k, 14k or 10k contain higher percentages of copper or other base metals or silver or palladium in the alloy.

Q15. What is the shape of sulphur hexafluoride molecule?
सल्फर हेक्साफ्लोराइड अणु का आकार क्या है?
(a) Trigonal pyramid / ट्राइजोनल पिरामिड
(b) Octahedral / ऑक्टाहेड्रल
(c) Planar / समतल
(d) Tetrahedral/ टेट्राहेड्रल
Ans.(b)
Sol. Sulphur hexafluoride (SF_6) is an inorganic, colourless, odourless and non-flammable compound. SF_6 has an octahedral shape. It has 12 electrons around the central Sulphur atom. This means there are six electron pairs arranged in an octahedral shape.

 

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