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Oct 19, 2016

2. Causes Of Refraction of Light Physics Class 10

Cause of Refraction : The speed of the light in different transparent substances is different. For example speed of light in air is 3×10⁸ m/s and that of in glass is 2×10⁸ m/s. It is clear that the two speeds of the light are different. When light enters from air to glass the speed of the light gets decreased at the junction of the two media. This change in speed of the light affects the speed the of the various segments of the beam of the light. This can be concluded by the image. This change in speed of the light causes refraction.

Causes Of Refraction of Light Physics Class 10
Therefore the refraction of light is due to the change in the speed of light on going from one medium to another.

Now it is good question why change in speed causes refraction. Here is the answer. If we look the image carefully. The left part of the beam of light enters first into another medium while its right part remains still in first medium here air. Therefore the speed of the left part of the beam experiences speed reduction before that of the right part of the beam. This causes less distance covered by left side beam and more distance traveled by right side beam.

Dear friend if you have any doubt , then comment please. Or you can give your suggestion about this part of the refraction of light.

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Oct 15, 2016

1 Refraction of Light Definition and Introduction Physics Class 10

Refract means bending. The bending of ray of light when it pass from one medium to another medium is known by a term called refraction.

Refraction of Light Definition and Introduction Physics Class 10

Refraction of Light happens due to different speed of light in different medium. Speed of light in air is 3x10⁸m/s and that of in glass is 2x10⁸m/s.

Refraction of Light: It can be defined as the change in the direction of light when it passes from one medium to another medium obliquely.

A transparent substance in which light can travel is called a medium. For example Air, water, glass, kerosene etc are the transparent substances in which light can travel.

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Oct 7, 2016

5.Heating Effect of Electric Current Physics Class 10

heating effect of electric current physics

Current flowing through a conductor produces heat. This heat depends on quantity of current flowing through the conductor, time and resistance of the conductor. We can write:
H α I²
H α R
H α t
By combining these three relation we get:
H α I²Rt
K= (H/(I²Rt))
K= H
for I=1 Amp., R= 1 ohm and t= 1 sec.
K becomes equal to heat generated at this condition. It is found heat generated is 0.24 calorie.
∴ H=0.24 I²Rt

This is also known as Jouls Law of Heating.

Also remember. 1 Calorie = 4.2 Joul

The above video contains explanation of heating effect of current through a conductor. The equation derivation is also shown.

Why 0.24 added while breaking proportionality is clearly explained.

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Important Mathematical Relations of Measurement

Important mathematical relations of measurement.

These are very important mathematical relations. It must be on the tongue of a student . These common relations are seen very frequently in the sum .

| Mass
1 Ton = 10 Quintals 1 Quintal = 100 Kg
1 Kg = 1000 g 1 pound = 453 g
1 Km = 1000 m 1m = 100 cm
1 feet = 12 inches 1 inch = 2.54 cm
1 yard = 3 feet
1 year = 365 days 1 month = 30 days
1 week = 7 days 1 hour = 60 min
1 min = 60 seconds 1 day = 24 hours
1 gross = 144 1 dozan = 12
Re 1 = 100 Paise
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Oct 4, 2016

Important Squares And Square Root Lower Grade Students Mathematics

Important Squares and their square root.

42 = 16 112 = 121
52 = 25 √(25)=5
62 = 36 √(36)= 6
72 = 49 √(49 ) = 7
82 = 64 √(64)= 8
92 = 81 √(81)= 9
102 = 100 √(100) = 10
112 = 121 √(121) = 11
122 = 144 √(144 ) = 12
132 = 169 √(169 ) = 13
142 = 196 √(196 ) = 14
152 = 225 √(225 ) = 15
162 = 256 √(256 ) = 16
172 = 289 √(289 ) = 17
202 = 400 √(400 ) = 20
252 = 625 √(625 ) = 25
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Oct 2, 2016

In Time of Adversity Question Answer Class 8

This chapter is about a letter written by a young lady; whose father was victim of this terror attack.

Q(01) Where was the writer's father when the terrorist attack took place? Who was with him?

Ans: The writer's father was at the Indian restaurant on the first floor of the Oberoi hotel when the terrorist attack took place. His two best friends were with him .They were having dinner together.

Q(02) How did the writer's father save himself? What were the qualities that helped him to protect?

Ans: The terrorist rounded up the hostages and made them to climb the service staircase, the eighteenth floor. On reaching the eighteenth floor landing ,they made the people line up against the wall then they opened fire on the people simultaneously . Her father was at the center of the line and body as soon as the firing began . He protected himself out of reflex or his presence of mind .    

Q(03)What did the writer's father and other survivors do to keep themselves alive till help arrived?

Ans:  When the terrorist left the landing after setting up explosive , the lady's father along with the three other survivors, climbed up the rest of the stairwell and discovered a large HVAC Plant room in which they decided to take shelter . They spent the rest of seige hiding in that room trying to get the attention of the world outside by waving a makeshift flag out of the window .They drank sips of dirty water from the Air conditioning unit to survive.

Q(04) The terrorists attacked people at every level .Explain this line in the context of the eventful day.?

Ans:  When terrorist attacked people they do not discriminate among them.They killed young kids and even the pregnant woman .They killed middle class workers at the railway station , elite in the hotels, tourist and kids in a cafe and sick and dying in the hospitals.They killed Indians, Americans, Britans and several other nationalities .Men, women, children, policeman,fireman and doctors etc were also killed.

Q(05) Q(05) What are the ideas behind every terror attack that the writer can recognise ? Do you agree with the writer's views? Justify your answer. .........

Ans:  The ideas behind every terror attack is the hatred anger and desperation of the terrorists and the cold-blooded targeted ruthlessness of these who sent them .They respect nothing but their own twisted beliefs to achieve them .They have declared war on every other way of life. Yes , I agree with the writer's views.     

Q(06) Why does the writer want to thank the readers? How have the readers helped the writer ? .

Ans:  Writer wants to thank the reader for the incredible concern and support that the readers have shown for the Mumbai victims when the whole of Mumbai was under terrorist attack. The reader helped the writer through their concern sympathy and prayers for the people of Mumbai who were under attack.     

Reference to the context -
(1) They communicated to each other by tough as they were too afraid to make a sound.

Q(a) Who does 'they' refer to??

Ans: Here 'they' referred to the survivors who survived from the mass murder of the terrorist at the eighteenth floor of the Oberoi hotel.

Q(b) Why were they afraid to make a ?

Ans: They were afraid to make a sound because a small sound in the room might bring back the terrorist would find that there were survivors , they would show no mercy and killed them.    

Q(c).What had happened to them ?

Ans:  The terrorist rounded up all the people of the Oberoi hotel and took them to the eighteenth floor landing. They made the people line up against the wall and opened fire on the people simultaneously.

(2) This was systematic, cold-blooded,slaughter.

Q(a) What is being described here?

Ans:  Here the writer describes a series of synchronized terror attack at various places in Mumbai.

Q(b) Why does the writer say so?

Ans:  The writer said so because terrorist attack people at every level. They did not show mercy to the children and the old.They killed middle-class workers , elite ,tourists and kids .They stormed three hospitals and killed the sick and dying .They did not discriminate among the different nationalities.They killed men, wonen , children, policeman, firemen , doctors.

(3) Over the next week....I hope the rest of the world does too.

Q(a) What is the writer talking about in these lines?

Ans: The writer is talking about the terrorist attack in Mumbai and the victims those who are killed .Writer wants everyone to pray for the souls of the ******.She also request everyone to help the victims who survived .She wants us to help them to come back to their normal life.

Q(b) Why does the writer want the world to do the same ?

Ans: Writers want world to do the same because terrorism is not a problem in any particular country . It is now a global war and people of every country are fighting to combat terrorism . So, it should be a joint fight and we should help one another to solve this global problem.   

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Sep 20, 2016

Lochinvar English Literature Question Answer Class 8

Q(01) Where was the Lochinvar going ?Why was he in such a hurry?

Ans: Lochinvar was going to the Netherby hall in marriage ceremony of fair Ellen. Lochinvar loves Ellen but Ellen’s father has forced Ellen to marry somebody else .Ellen ,that day is getting married at the Netherby Hall .So ,Lochinvar is in a hurry to reach there.

Lochinvar English Literature Question Answer Class 8

Q(02) Describe the exchange that took place between the bride’s father and Lochinvar , when the latter entered Netherby Hall.

Ans: When Lochinvar entered the Netherby Hall , the bride’s father stopped him and asked him whether Lochinvar had come there to have a war with them or he had come there ina peaceful and jovial mood to dance at the marriage party .Lochinvar’s replied was that he had loved Ellen at one time but then the love had decreased like a low tide .Many young beautiful women in Scotland are eager to marry him .So, Lochinvar had come there to dance and have a cup of wine at the party.    

Q(03)Did Lochinvar mean what he said?

Ans:  No, Lochinvar did no mean what he said because he still loved Ellen and he had come to take her away along with him.

Q(04) What did young Lochinvar tell the bride?

Ans:  The young Lochinvar drank the wine which the bride had offered him .He then took her safe hand and asked her to dance with him.

Q(05) How did the bride’s parents react to Lochinvar’s action?

Ans:  Ellen’s mother wanted to stop Ellen from dancing with Lochinvar ,but she could not so both the parents fumed in anger.     

Q(06)When Lochinvar and bride began to dance ,what did the bridesmaid said?

Ans:  When Lochinvar and the bride began to dance ,the bridesmaid whispered that it could have been better if their fair cousin was married with the young Lochinvar .     

Q(07) How did Lochinvar manage to ride off with his lady love?

Ans:  While dancing with Ellen ,young Lochinvar whispered something to Ellen’s ear and they both reached the hall’s door .The horse of Lochinvar was standing near the door. Lochinvar very easily put Ellen on horse back and he himself sat in front of her .Then They both rode away from there.     

Q(08) What happened after Lochinvar rode away with the bride ?

Ans:  When Lochinvar rode away with the bride , soldiers from Netherby Hall chased them on the order of Ellen’s father .The soldiers persued Lochinvar through many villages. There was racing and chasing on Connobie Lee but they were not able to catch the couple.     

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Sep 15, 2016

Essay on Importance of Game in Our Life | हमारे जीवन में खेल का महत्व पर निबंध

खेल मनोरंजन के स्रोत हैं। वे राहत और दुख, कठिनाइयों और बाधाओं से हमको बचाते हैं। वे विनोदी भावना मन में न बैठाने और एक हल्के-फुल्के अंदाज में जीवन के भारी बोझ को लेने के लिए प्रेरित करते हैं। जीने को साधारण व्यवसाय के रूप में लेने की प्रेरना भी प्रदान करते हैं। यह स्वास्थ्य और शारीरिक फिटनेस बनाए रखने के लिए आवश्यक है। यह टीम भावना के विकास को प्रोत्साहित करती है।

आउटडोर गेम्स: आउटडोर खेल जैसे फुटबॉल, वॉली, क्रिकेट, बास्केट बॉल और टेनिस आदि दुनिया भर में बहुत लोकप्रिय हैं। हाल ही में, विश्व कप फुटबॉल सभी खेल प्रेमियों के लिए ध्यान का केन्द्र बिन्दु था। टेबल टेनिस दुनिया के कई हिस्सों में खेला जाता है।

Essay on Importance of Game in Our Life

ओलिंपिक खेलों को 4 साल के अंतराल के साथ आयोजित किया जाता है। यह एकता की भावना और राष्ट्रों के बीच सच्चे विनोद की भावना को बढ़ावा देता है।

खेल को प्राथमिक कक्षाओं से शैक्षिक पाठ्यक्रम के एक भाग के रूप में अनिवार्य किया जाना चाहिए। शुरू से ही बच्चों को खेल और खेल की उपयोगिता का एहसास होना चाहिए। खेल-कूद से अनुशासन, साथी-भावना और एकजुटता की भावना प्रदान होती है। वे समय के मूल्य को पढ़ाने और यह नोट करने के लिए कि कैसे एक मिनट, एक मिनट का एक अंश और यहां तक की दूसरे की प्रतियोगिता के क्षेत्र में एक युवा खिलाड़ी के भाग्य का फैसला करने में महत्वपूर्ण है। खेल और खेल में उचित प्रशिक्षण के साथ, छात्र सक्रिय, विनोदी, तेज़, साहसी और साहसिक भविष्य के जीवन में चुनौतियों को पूरा करने में सक्षम हो जाते हैं।

इसे ध्यान में रखते हुए, यह उच्च समय है कि हम अपने खेल प्रतिभाओं को बाहर हाज़िर करें और उन्हें संशय की भावनाओं के साथ विश्व चैंपियन के साथ प्रतिस्पर्धा करने के लिए सक्षम करने के लिए सभी आवश्यक सुविधाएं प्रदान करें।

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Aug 29, 2016

Essay on If I had Wings In Hindi| यदि मेरे पंख होते निबन्ध हिंदी में

जब छोटे थे हम मन में एक सवाल आता था आसमान को देख कर, यदि मेरे पंख होते तो क्या होता? अगर होते तो वो बड़े अनोखे होते। वो कभी न थमते, न कभी मुझे किसी के हाथ आते। बस उड़ा ले जाते मुझे जहाँ मेरा मन होता। जब स्कूल जाना होता, तो किसी से बिन बताये ले जाते मुझे ये उस पार्क में जहाँ सबसे ज्यादा झूलें होते और झूलने के लिए अपनी बारी का इंतज़ार भी न करना पड़ता क्योंकि तब सब बच्चे स्कूल में पढ़ रहे होते।

ये पंख मिल जाते तो हवाई जहाज़ का सफर मुफ्त में होता। मैगज़ीन में जिस देश की फोटो थी, वो देश देख लिया होता। हवा मेरा ठिकाना होती, बस पैर कभी ज़मीन पे न टिकते। माँ को रोज़ कहीं न कहीं घुमा आते मैं और मेरे ये पंख। अपने बेस्ट फ्रेंड को उसके जन्म दिन पर एक दिन के लिए तोहफ़े में इन पंखों की उड़ान दे दी होती। ठंडी हवाओं में बस मैं और मेरी उड़ान होती। रोड क्रॉस करने में डर नहीं लगता क्योकि क्रॉस ही नहीं करनी पड़ती। बस हवा में हर जगह पहुँच होती मेरी। रुई जैसे बादल को अपने हाथों से छुने को मिलता। किसी बादल को आइस-क्रीम तो किसी को साइकिल बना लेते हाथों से।

Essay on If I had Wings In Hindi

मन करता की जल्दी-जल्दी हर जगह घूमना हो जाता। मेरी उड़ानों के दौरान हर सुन्दर नज़ारा मेरी आँखों के सामने से गुज़रता। पकड़म-पकड़ाई में कोई मुझे नहीं पकड़ पाता। छुपन-छुपाई खेलते हुए पेड़ों पर बड़े आराम से छिपना हो जाता। बारिश होती तो ऊपर उड़ान भरने पर समझ आ जाता कि आखिर ये बारिश होती कैसे है। किताबों से जानना नहीं पड़ता। सब सामने आसमानों में ही देखने को मिल जाता।

आज ऐसे लगता है, है तो पंख मेरे पास। मेरा ज्ञान, मेरी सोच। मैं सिर्फ शरीर तो नहीं, आत्मा हूँ। मेरे पंख मेरा ज्ञान और मेरी सोच ही तो हैं जो नजाने कहाँ-कहाँ ले जाते हैं मुझे। कितना कुछ मुझे दिखाते हैं। ज्ञान है तो, समझ होती है, हमारे कदम बस बढ़ते ही रहते हैं। पँखों की शक्ल में लगे हैं हर वक़्त, जो कोई काट नहीं सकता, अलग नहीं कर सकता। न तो ये तोड़े जा सकतें हैं, ना ही मरोड़े जा सकतें हैं क्योंकि कभी किसी के हाथ ही नहीं आ सकते। हर देश विदेश ले जा सकते हैं। सोच ही तो है, जितनी बड़ी उतना ऊँचा ले जाती है। मेरे पंख मेरे पास ही हैं । दिखते तो नहीं पर मेरे साथ ही हैं । बस ये और बड़े हो जाएँ और मुझे हर जगह ले जाए ।

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Aug 14, 2016

मेरी यादगार यात्रा पर निबंध | Essay on My Memorable Tour in Hindi

यात्रा का अपना एक सुखद अनुभव होता है। हर यात्रा अपने में कई यादें समेटे होती है पर कुछ बहोत यादगार होती हैं ।गर्मी की छुट्टियों में अधिकतर लोग घूमने जाते हैं और इस मौसम में पर्वतों की यात्रा अत्यधिक सुखद होती है। हमारी पहली पर्वतीय यात्रा पिछले वर्ष गर्मी की छुट्टियों में हुई जब पिताजी के पुराने मित्र ने नैनीताल में अपने आवास पे एक समारोह रखा और पिताजी को आमंत्रित करने के साथ साथ ज़रूर आने का आग्रह भी किया।

पिताजी ने इस आग्रह का सम्मान करते हुए समारोह में जाने के लिए और साथ साथ नैनीताल घूमने के लिए पांच दिन की योजना बनायी। हमने 20 मई को नैनीताल के लिए रेल पकड़ी और अगले दिन सुबह 10 बजे वहां पहुँच गए। स्टेशन पे पिताजी के मित्र हमें लेने आये हुए थे।

हम उनके साथ उनके घर गए। उन्होंने पिताजी की योजना की सराहना करते हुए उन्हें आने के लिए धन्यवाद कहा और हमें नैनीताल घुमाने की जिम्मेदारी अपने ड्राइवर को सौंप दी। क्योंकि समारोह तीन दिन बाद था तो हम नैनीताल घूमने निकल गए। नैनीताल के रास्ते बहुत टेड़े मेढ़े थे और रास्ते के दोनों ओर घाटियों का मनमोहक दृश्य था। कहीं ये घाटियां अत्यंत सुन्दर थीं और कहीं इनकी गहरायी डरा देने वाली थी। पर्वतों पर पेड़ों की सुंदरता देखते ही बनती थी। गर्मी के मौसम में भी शीतल हवायें मन को अत्यंत सुख दे रही थीं। नगर की सड़कें स्वछ थीं और घर साफ़ सुथरे थे नैनीताल का नाम एक ताल के कारण पड़ा जो वहां पर है जिसका नाम भी नैनीताल है। इसी ताल के एक किनारे पे नयना देवी का मंदिर है। मंदिर के बहन अत्यंत खूबसूरत पर्वत हैं जो सबका मन मोह लेते हैं। उसके अलावा भी नैनीताल मैं कई स्थल हैं जो बेहद मनमोहक हैं। तीन दिन हम काफी घूमे। उसके बाद पिताजी के मित्र के यहाँ समारोह मैं सम्मिलित होकर हमने अगले दिन घर के लिए रेल पकड़ी।

नैनीताल की यह यात्रा मेरे लिए बहुत सुखद और यादगार रही। वहां की प्राकृतिक सुंदरता ने मन मोह लिया और वहां के दृस्यों को मैं कैमरे में कैद कर लिया। अवसर मिलने पर मैं एक बार फिर ऐसी सुखद यात्रा पे वहां अवश्य जाना चाहूंगा।

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