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 1,27,278 seats to be filled by the valid candidates. Opportunity is here but you have to welcome it with a provident strategy.
Q1. Sky is blue because-
आकाश नीला है क्योंकि
(a) Blue colour in the sunlight is more than other colours/सूर्य के प्रकाश में नीला रंग अन्य रंगों से अधिक है
(b) Short waves are scattered more than long waves by atmosphere/वायुमंडल द्वारा लघु तरंगे लंबी तरंगों से अधिक फैलेती हैं
(c) Blue colour is more absorbing to eyes/नीला रंग आंखों के लिए अधिक अवशोषित है
(d) Atmosphere absorbs long wavelength more than short wavelength/वायुमंडल लघु तरंगदैर्ध्य की तुलना में लंबी तरंगदैर्ध्य को अधिक अवशोषित करता है
आकाश नीला है क्योंकि
(a) Blue colour in the sunlight is more than other colours/सूर्य के प्रकाश में नीला रंग अन्य रंगों से अधिक है
(b) Short waves are scattered more than long waves by atmosphere/वायुमंडल द्वारा लघु तरंगे लंबी तरंगों से अधिक फैलेती हैं
(c) Blue colour is more absorbing to eyes/नीला रंग आंखों के लिए अधिक अवशोषित है
(d) Atmosphere absorbs long wavelength more than short wavelength/वायुमंडल लघु तरंगदैर्ध्य की तुलना में लंबी तरंगदैर्ध्य को अधिक अवशोषित करता है
Ans.(b)
Sol. Blue light which has the least wavelength of all the visible radiations is scattered most. The blue appearance of the sky is due to scattering of sunlight from the atmosphere. Light of shorter wavelength is scattered by air molecules which because of their smaller size follow Rayleigh’s scattering. Blue light is strongly scattered by the air molecules and reach the observer. This explains the blue colour of the sky.
Sol. Blue light which has the least wavelength of all the visible radiations is scattered most. The blue appearance of the sky is due to scattering of sunlight from the atmosphere. Light of shorter wavelength is scattered by air molecules which because of their smaller size follow Rayleigh’s scattering. Blue light is strongly scattered by the air molecules and reach the observer. This explains the blue colour of the sky.
Q2. The change of focal length of an eye lense is caused by action of the
एक नेत्र लेंस की फोकल दुरी में परिवर्तन किसके कारण होता है
(a) Pupil/आंख की पुतली
(b) Retina/दृष्टिपटल
(c) Ciliary muscles/कैलीरी मांसपेशियों
(d) Iris/आइरिस
Show Answer
Ans.(c)
Sol. The eye lens is composed of a fibrous, jelly-like material. Its curvature can be modified to some extent by the ciliary muscles. The change in the curvature of the eye lens can thus change its focal length. When the muscles are relaxed, the lens becomes thin. Thus its focal length increases. This enables us to see distant objects clearly. When you are looking at objects closer to the eye, the ciliary muscles contract. This increases the curvature of the eye lens. The eye lens then becomes thicker. Consequently, the focal length of the eye lens decreases. This enables us to see nearby objects clearly.
Sol. The eye lens is composed of a fibrous, jelly-like material. Its curvature can be modified to some extent by the ciliary muscles. The change in the curvature of the eye lens can thus change its focal length. When the muscles are relaxed, the lens becomes thin. Thus its focal length increases. This enables us to see distant objects clearly. When you are looking at objects closer to the eye, the ciliary muscles contract. This increases the curvature of the eye lens. The eye lens then becomes thicker. Consequently, the focal length of the eye lens decreases. This enables us to see nearby objects clearly.
Q3. Waves used for telecommunication are-
दूरसंचार के लिए उपयोग की जाने वाली तरंगे-
(a) Visible light /दृश्य प्रकाश
(b) Infrared/इन्फ्रारेड
(c) Ultraviolet/पराबैंगनी
(d) Microwave/माइक्रो तंरग
Show Answer
Ans.(d)
Sol. The microwaves are high-frequency signals in the 300 MHz to 300 Ghz range. The signals can carry thousands of channels at the same time, making it a very versatile communication system. Microwave is often used for point-to-point telecommunications. Today microwave is employed by telecommunication industry in the form of both terrestrial relays and satellite communication.
Sol. The microwaves are high-frequency signals in the 300 MHz to 300 Ghz range. The signals can carry thousands of channels at the same time, making it a very versatile communication system. Microwave is often used for point-to-point telecommunications. Today microwave is employed by telecommunication industry in the form of both terrestrial relays and satellite communication.
Q4. A dynamo which is said to generate electricity actually acts as a
बिजली उत्पन्न करने वाला डायनेमो वास्तव में किसके रूप में कार्य करता है:-
(a) Source of ions/आयनों का स्रोत
(b) Source of electric charge/विद्युत आवेग का स्रोत
(c) Converter of energy/ऊर्जा के परिवर्त्तक
(d) Source of electrons/इलेक्ट्रॉनों के स्रोत
Show Answer
Ans.(c)
Sol. A dynamo, which is also known as an electrical generator produces direct current through a commutator. It is basically a device which converts mechanical rotation into electric current according to Faraday’s law.
Sol. A dynamo, which is also known as an electrical generator produces direct current through a commutator. It is basically a device which converts mechanical rotation into electric current according to Faraday’s law.
Q5. The technique used to transmit audio signals in television broadcast is-
टेलीविज़न प्रसारण में ऑडियो सिग्नल संचारित करने के लिए किस तकनीक का इस्तेमाल होता है -
(a) Amplitude modulation/आयाम मॉड्यूलन
(b) Pulse code modulation/पल्स कोड मॉडुलेशन
(c) Frequency modulation/आवृति मॉडुलेशन
(d) Time dimension multiplication/समय आयाम बहुलीकरण
Show Answer
Ans.(c)
Sol. Television broadcasts emit two types of signals, audio and visual. These two signals require modulation to transmit both signals at the same time. Analog television requires transmission that uses specific modulation methods employing AM and FM signals in its transmission. Frequency modulation or FM is used for the audio part of the transmission. Amplitude modulation or AM is used in the video transmission.
Sol. Television broadcasts emit two types of signals, audio and visual. These two signals require modulation to transmit both signals at the same time. Analog television requires transmission that uses specific modulation methods employing AM and FM signals in its transmission. Frequency modulation or FM is used for the audio part of the transmission. Amplitude modulation or AM is used in the video transmission.
Q6. Xeric condition refers to-
जेरिक स्थिति किसको संदर्भित करता है?
(a) low temperature /कम तापमान
(b) low humidity /कम आर्द्रता
(c) high evaporation /उच्च वाष्पीकरण
(d) extreme temperature mperature as high as 138 K. /चरम तापमान 138 K के समान उच्च
Show Answer
Ans.(b)
Sol. Xeric condition refers to low humidity. Xeric environment is place where water is meager.
Sol. Xeric condition refers to low humidity. Xeric environment is place where water is meager.
Q7. A body floats at 4°C water. If temperature reaches 100°C then-
एक वस्तु 4 डिग्री सेल्सियस तापमान के पानी पर तैरती है। यदि तापमान 100 डिग्री सेल्सियस तक पहुंच जाए है तो-
(a) The body will sink /वस्तु डूब जाएगी
(b) No change /कोई बदलाव नहीं
(c) Less part of the body will submerge /वस्तु का कम भाग डूब जाएगा
(d) The body will float freely/वस्तु स्वतंत्र रूप से तैरेगी
एक वस्तु 4 डिग्री सेल्सियस तापमान के पानी पर तैरती है। यदि तापमान 100 डिग्री सेल्सियस तक पहुंच जाए है तो-
(a) The body will sink /वस्तु डूब जाएगी
(b) No change /कोई बदलाव नहीं
(c) Less part of the body will submerge /वस्तु का कम भाग डूब जाएगा
(d) The body will float freely/वस्तु स्वतंत्र रूप से तैरेगी
Show Answer
Ans.(a)
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.
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.
Q8. A cut diamond shines brilliantly due to-
तरासा गया हीरे किसके कारण अत्यधिक चमकता है?
(a) Total internal reflection /पूर्ण आंतरिक परावर्तन
(b) Absorption of light /प्रकाश के अवशोषण
(c) Some inherent property /कुछ अंतर्निहित गुण
(d) Its molecular structure/इसकी आणविक संरचना
तरासा गया हीरे किसके कारण अत्यधिक चमकता है?
(a) Total internal reflection /पूर्ण आंतरिक परावर्तन
(b) Absorption of light /प्रकाश के अवशोषण
(c) Some inherent property /कुछ अंतर्निहित गुण
(d) Its molecular structure/इसकी आणविक संरचना
Show Answer
Ans.(a)
Sol. The refractive index of diamond is very high. Diamond achieves brilliance partially from total internal refraction. It has been cut or designed in such a way that if light enters into it, incident light strikes many of the internal surfaces.
Sol. The refractive index of diamond is very high. Diamond achieves brilliance partially from total internal refraction. It has been cut or designed in such a way that if light enters into it, incident light strikes many of the internal surfaces.
Q9. The clouds float in the atmosphere because of their low :
बादल वायुमंडल में किसके कारण में तैरते है?
(a) Temperature /निम्न तापमान
(b) Velocity /निम्न वेग
(c) Pressure /निम्न दबाव
(d) Density/निम्न घनत्व
बादल वायुमंडल में किसके कारण में तैरते है?
(a) Temperature /निम्न तापमान
(b) Velocity /निम्न वेग
(c) Pressure /निम्न दबाव
(d) Density/निम्न घनत्व
Show Answer
Ans.(d)
Sol. Clouds from when the invisible water vapour in the air condenses into visible water droplets. They are so small that the effect of gravity on them is negligible. Thus the clouds float in the atmosphere because of their low density.
Sol. Clouds from when the invisible water vapour in the air condenses into visible water droplets. They are so small that the effect of gravity on them is negligible. Thus the clouds float in the atmosphere because of their low density.
Q10. Who discovered Television?
टेलीविजन की खोज किसने की?
(a) Edison /एडिसन
(b) Galileo/गैलीलियो
(c) Baird /बेयर्ड
(d) Franklin/फ्रैंकलिन
Show Answer
Ans.(c)
Sol. Television was invented by J.L. Baird in 1926 in Britain. Galileo invented the Telescope.
Sol. Television was invented by J.L. Baird in 1926 in Britain. Galileo invented the Telescope.
Q11. When water is heated from 0°C to 10°C. It’s volume:
जब पानी को 0 डिग्री सेल्सियस से 10 डिग्री सेल्सियस तक गर्म किया जाता है तो इसका आयतन:
(a) Increases/बढ़ता है
(b) Decreases/घटता है
(c) Does not change/अपरिवर्तित रहता है
(d) First decreases and then increases/पहले घटता है और फिर बढ़ता है
जब पानी को 0 डिग्री सेल्सियस से 10 डिग्री सेल्सियस तक गर्म किया जाता है तो इसका आयतन:
(a) Increases/बढ़ता है
(b) Decreases/घटता है
(c) Does not change/अपरिवर्तित रहता है
(d) First decreases and then increases/पहले घटता है और फिर बढ़ता है
Show Answer
Ans.(d)
Sol. When water is heated from 0°C to 4°C, then there is a decrease in volume and increases in density but when we cross the limit of 4°C its volume increases and density decreases. Thus, when water is heated from 0°C to 10°C, it’s volume first decreases and then increases.
Sol. When water is heated from 0°C to 4°C, then there is a decrease in volume and increases in density but when we cross the limit of 4°C its volume increases and density decreases. Thus, when water is heated from 0°C to 10°C, it’s volume first decreases and then increases.
Q12. Principle of fuse is
फ़्यूज़ का सिद्धांत क्या है
(a) Chemical effect of electricity/विद्युत का रासायनिक प्रभाव
(b) Mechanical effect of electricity/विद्युत के यांत्रिक प्रभाव
(c) Heating effect of electricity/विद्युत के तापीय प्रभाव
(d) Magnetic effect of electricity/विद्युत के चुंबकीय प्रभाव
फ़्यूज़ का सिद्धांत क्या है
(a) Chemical effect of electricity/विद्युत का रासायनिक प्रभाव
(b) Mechanical effect of electricity/विद्युत के यांत्रिक प्रभाव
(c) Heating effect of electricity/विद्युत के तापीय प्रभाव
(d) Magnetic effect of electricity/विद्युत के चुंबकीय प्रभाव
Show Answer
Ans.(c)
Sol. The electric fuse works on the principle of the heating effect of electric current. It consists of a piece of wire made of a metal or an alloy of low melting point. As the current increases beyond a limit, the wire in the electric fuse melts and breaks off.
Sol. The electric fuse works on the principle of the heating effect of electric current. It consists of a piece of wire made of a metal or an alloy of low melting point. As the current increases beyond a limit, the wire in the electric fuse melts and breaks off.
Q13. The characteristic of super conductor is-
सुपर कंडक्टर की क्या विशेषता है -
(a) High permeability / उच्च पारगम्यता
(b) Low permeability / कम पारगम्यता
(c) Zero permeability / शून्य पारगम्यता
(d) Infinite permeability /अनंत पारगम्यता
Show Answer
Ans.(c)
Sol. It is represented by Greek letter μ(Mu). The permeability μ of the super conductor is zero.
Sol. It is represented by Greek letter μ(Mu). The permeability μ of the super conductor is zero.
Q14. The smallest unit of length is-
लंबाई की सबसे छोटी इकाई है-
(a) Micron / माइक्रोन
(b) Nanometre / नैनोमीटर
(c) Angstrom / ऐंग्स्ट्रॉम
(d) Fermimetre /फर्मीमीटर
लंबाई की सबसे छोटी इकाई है-
(a) Micron / माइक्रोन
(b) Nanometre / नैनोमीटर
(c) Angstrom / ऐंग्स्ट्रॉम
(d) Fermimetre /फर्मीमीटर
Show Answer
Ans.(d)
Sol. 1 Micron = 10^(–6) metre
1 Nanometre = 10^(-9) metre
1 Angstrom = 10^(-10) metre
1 Fermimetre = 10^(-15) metre
Thus, the smallest unit of length in the given options is fermi metre.
Sol. 1 Micron = 10^(–6) metre
1 Nanometre = 10^(-9) metre
1 Angstrom = 10^(-10) metre
1 Fermimetre = 10^(-15) metre
Thus, the smallest unit of length in the given options is fermi metre.
Q15. Sound waves-
ध्वनि तरंगे-
(a) Can travel in vacuum/वैक्यूम में यात्रा कर सकती हैं
(b) Can travel only in solids/केवल ठोस में यात्रा कर सकती हैं
(c) Can travel only in gases./केवल गैसों में यात्रा कर सकती हैं
(d) Can travel both in solid and gaseous medium./ठोस और गैसीय मध्यम दोनों में यात्रा कर सकती हैं.
ध्वनि तरंगे-
(a) Can travel in vacuum/वैक्यूम में यात्रा कर सकती हैं
(b) Can travel only in solids/केवल ठोस में यात्रा कर सकती हैं
(c) Can travel only in gases./केवल गैसों में यात्रा कर सकती हैं
(d) Can travel both in solid and gaseous medium./ठोस और गैसीय मध्यम दोनों में यात्रा कर सकती हैं.
Show Answer
Ans.(d)
Sol. Sound waves need to travel through a medium such as a solid, liquid or gas. The sound waves travel through each of these mediums by vibrating the molecules in the matter.
Sol. Sound waves need to travel through a medium such as a solid, liquid or gas. The sound waves travel through each of these mediums by vibrating the molecules in the matter.
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