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Three sum of electrical power have been discussed. Here. These sum will give a basic idea of finding electrical power and electrical energy consumed by a load or electrical energy supplied by a source like battery.
The sums are:
1. Two resisters of value 6 ohm and 12 ohms are connected in series across a battery of 12 volt. Draw the circuit diagram and calculate.
a) Current flowing through each resistor.
b) The electrical energy consumed by each resistor.
+ Sollution- Close the Sollution 2. These two resistors again connected in parallel and the above data are again calculated.
+ Sollution- Close the Sollution 3. Two bulb L1 and L2 of rating 100 W 200 V and 10 W 200 Volt respectively are connected across a supply of 200 V in series. Find
a) Current flowing through each bulb
b) which bulb will consume more power.

There are two laws of refraction of light. these are :
a) Incident say , refracted ray and normal lie on same plane .
The concept of plane is shown in the image. In terms of x,y and z co-ordinate system , the y-z plane is shown in light sky blue colour. We write on our copy which is considered x-y plane. The image is given just for understanding of plane concept. It is not needed while writing the law. Try to image other planes in the image.
b) Ratio of sin of angle of incidence and sine of angle of refraction remains constant for a pair of media. i.e. sin i / sin r = constant (n)
this constant is called refractive index of medium 2 with respect to medium 1.
or we can write
n2 / n 1 = sin i / sin r
Where n 1 is the refractive index of first medium here air. And n2 is the refractive index of second medium here glass.
∴ n2 = n1 x ( sin i / sin r )
If you have any query regarding the laws of refraction then comment below.

There are many effects of the refraction of life in our day to day life. For example I am citing few of them.
a) The partly immersed stick appear to be bend at the surface of the water.
b) The coin kept in water appears raised upward.
c)The water of a pool appear less depth.
d)Stars appear to twinkle in the sky when the sky remains clear.
e)A lemon immersed in water appears to be bigger in size.
All these are discussed in the above video. If you have any confusion then comment below.

Case1: When ray of light travels from rarer medium like air to a denser medium like glass then it bends towards normal.Case 2: When ray of light travels from denser medium like glass to a rarer medium like air then it bends away from the normal.Case 3: When ray of light travels from rarer medium like air to a denser medium like glass and again emerges to the previous rarer medium then it suffers a lateral displacement as shown in the figure.

लक्ष्य की उंचाई सफलता को गति और उर्जा प्रदान करती है। परन्तु ऐसा लक्ष्य जो किसी बच्चे की क्षमता से अत्यधिक है । वह बच्चे को मानसिक रोगी या पागल बनाता है । और कभी कभी बच्चे आत्महत्या का शिकार हो जाते हैं। इसलिए मेरा मानना है कि इस तरह का दबाव अनुचित है। जब जीवन ही नहीं रहेगा तो जीवन में लक्ष्य का कोई मतलब नहीं है। जब लक्ष्य बच्चे की क्षमता की परिधि के बाहर होता है , तो वह लक्ष्य उसके लिए बोझ बन जाता है । चुंकि बच्चे अपने माता पिता को खुश देखना चाहते हैं, इसलिए वे झूठ बोलने लगते हैं। जैसे मैने याद कर लिया, होमवर्क कर लिया , मै नकल नहीं करता हूं , मै 90% से जादा अंक प्राप्त करूंगा इत्यादि। इस दबाव में वे अपने अन्दर छुपी मेधा को पररव नहीं पाते । और माता पिता के सोंच के ढांचे में फंस जाते हैं। और नौकरी की खोज में दर दर भटकते रहते हैं। आज के इस प्रतिस्पर्धा के कारण दूसरेआम बच्चे थोड़ा तकनीकी सीखकर रोजी रोटी की दौड़ में इस बच्चे से आगे निकल जाते हैं। और सबसे बड़ी बात यह है कि वे निम्न और कमजोर मानसिकता के शिकार नहीं बनते। मेरे अनुसार ऊंचे लक्ष्य को अपने बच्चे की क्षमता के अनुसार निश्चित…

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. 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…

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 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.

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 . | Mass1 Ton = 10 Quintals 1 Quintal = 100 Kg 1 Kg = 1000 g 1 pound = 453 gDistance 1 Km = 1000 m 1m = 100 cm 1 feet = 12 inches1 inch = 2.54 cm 1 yard = 3 feetTime 1 year = 365 days 1 month = 30 days 1 week = 7 days 1 hour = 60 min 1 min = 60 seconds1 day = 24 hoursCountable 1 gross = 1441 dozan = 12 Re 1 = 100 Paise

Important Squares and their square root.

42 = 16112 = 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

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 …

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. 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 sa…

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। 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 …

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। मन करता की जल्दी-जल्दी हर जगह घूमना हो जाता। मेरी उड़ानों के द…

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 औ…

Newton's third law : 'To every action there is an equal and opposite reaction.'
This law can be realised while dropping a ball, hammering a nail , holding a hose pipe of high pressurised water pump , during bicycling etc. Suppose a man pushes an object with a force F, then the object react to this force with an equal and opposite of that force. That means if the man pushes the object with a force F12 then the object pushes him back with the same force F12 but as it is opposite to the direction of the man's force therefore it can be represented as -F12 . See the image.
Now we will explain the three case as shown int the video. You can also watch the video.
Case 1 [Hose Pipe]: When a man holds a hose pipe of high speed water rushing out from the pipe. The stream of water jet put an action on the hand of the man. Due to this action the man's hand pushes backward. Due a contact between pipe and the man's hand a reaction is produced that helps in holding th…

By Helen Keller This tale recounts Helen Keller’s discovery of language, through the teaching of Annie Sullivan, after losing her sight and hearing in early childhood. When the Helen family comes to know about the illness, they are flabbergasted. Helen is sent to a blind school where she meets with a teacher Annie Sullivian. Helen is lost and often throws tantrums but Annie reaches out to her through language. She teaches Helen to hand-spell many words. Helen follows pursuit like a memorising game. Next annie tries to teach her discipline. But having brought up as a lone child in her house, Helen throws tantrums and out of force of habit she throws the pitch of water at Annie. Annie forces Helen to refill the jar, when Helen realises that each and every item has a name. In the end, Annie and Helen travel to the Perkinsons institute and Helen realises that she is not alone anymore.

Rating of Electrical Appliance:These are normal rating of electrical appliances available in the market. Electric bulb-100W, 60W, 15W
Fluorescent tube- 40W, 20 W, 80W
CFL lamp- 5W, 15W, 20 W, 40W, 90W
Refrigirator- 220 W
Micro Oven- 3000 W
Electric Iron- 700W
Induction Heater - 1500 W From the rating of the electrical appliance , we can calculate the resistance of the filament, current flowing through the filament.

Also electrical energy consumed (WHr) can be calculated by multiplying the watt and duration of time in hour.

By converting the energy into bigger unit i.e. KWHr , the practical unit consumption of our houses can be find out. This is called KWhr or unit of electrical energy.

Today's average rate of electricity is around Rs 7.50 / unit.
It means if 200 unit reading is on the electric meter. It means we need to pay 200*7.5+ constant charge for maximum demand.
Rs 1500+ 100 = Rs 1600 approx.
The constant charge varies for maximum demand allowed …

Q(01). What was the unusual activity that Helen could sense? What were her reasons for sensing it? Ans: Helen sensed the arrival of her teacher Anne Sullivan. She could also sense it from her mother’s hurried movements. Q(02). How does Helen describe her life before the arrival of her teacher? Ans: She compares herself to a groping ship in a dense fog before the arrival of her teacher. In the utter confusion of her life, she craved for light. Q(03). Which incident ignited the desire in Helen to learn more about the things around her? Ans: Helen kept confusing the two terms ‘mug’ and ‘waters’. She would be in a frenzy when she could not make them out exactly. Being panicked Helen was led to the well-house by her teacher and made her feel the gush of water on her hand. This incident ignited a desire in Helen to learn more. Q(04). Mention an incident in the text which proves that Helen’s parents were over-indulgent towards her.Ans…

१. गर्मियों की छुट्टियाँ मुझे बहुतपसंद है|२. ये हमारी वार्षिक परीक्षा के बाद आती है|३. हम इसमे नानी के घर जाते है| नानी हमे कहानी सुनाती है|४. गर्मियों की छुट्टियों मे आइस क्रीम खाते है|५. इसमे हम अपने दोस्तो के साथ केरम , विडिया गेम,साँप सीढ़ी और अन्य कई सारे खेल खेलते है|६. हम परिवार के साथ हर साल हील स्टेशन जाते है| जहा हम नयी नयी जगह घूमते है , शॉपिंग करते है| फॅमिली फोटो लेते है|७. गर्मी की छुट्टियों मे हम हॉबी क्लास भी ज्वाइन करते है| जेसे :- तैराकी(स्वीमिंग), कला शिक्षा (आर्ट क्लास), इत्यादि| ८. गर्मी की छुट्टियों मैं देर तक सोने का मज़ा भी बहुत अलग होता है| रोज़ प्रातः जल्दी उठकर स्कूल नही जाना होता है|९.माँ भी बहुत सारे पकवान बना कर खिलती है| १०. शाम को हम दादा-दादी के साथ टहलने बगीचे मे जाते है और झूलो का आनंद लेते है| ११. हम इस बार गर्मी की छुट्टियो मैं घर के बगीचे मैं पौधे भी लगाएगे|१२. छुट्टियों मैं बिद्द्यालय से मिला होम वर्क हम सभी दोस्त साथ मिलकर करते है|१३. इस बार की छुट्टियो मैं मेरे घर पर चिड़िया ने बच्चे दिए थे, हम उनको रोज़ दाना डालते थे|१४. मेरी बहन का जन्मदिन भ…

दृश्य सिमरन के घर का है। सिमरन के घर उसकी पुरानी सहेली शहनाज़ आई है। दोनों ने एक ही कॉलेज से पढाई पूरी की है। सिमरन की शादी ग्रेजुएशन पूरी होने के बाद ही हो गई, और शहनाज़ ने आगे काम करने की ठान रखी थी; सो उसने ऐसा ही किया। ३ साल बाद आज शहनाज़ की भी शादी हो चुकी है। शहनाज़ शादी के बाद पहली बार अपनी सहेली सिमरन से मिलने उसके घर आई है , अपने देवर की बेटी रुनझुन के साथ। शहनाज़ की शादी उसके पड़ोस के मोहल्ले में ही हुई है , तो वह लगभग हर दूसरे दिन अपने मायके आ जाया करती है। आज रुनझुन को लेकर वो अपनी सहेली के साथ पुरानी यादें ताज़ा करने आई है। सिमरन : नमस्ते !
शहनाज़ : नमस्ते अज़रा!
सिमरन : कैसी हो? कितने दिनों बाद दर्शन हुए तुम्हारे। कहाँ हो आजकल ? तुम ना , शादी के बाद एकदम ईद का चाँद ही हो गई हो।
शहनाज़ : अरे नहीं अज़रा। दरअसल, शादी के बाद मैं तीसरे दिन ही ऑफिस के काम से बैंगलोर चली गई थी।
हालाँकि ये लम्बा प्रोजेक्ट था , पर मैंने काफी धीरज रखा। तीन महीने बाद आई हूँ वापस। सिमरन : अच्छा , तो ये बात है ! मोहतरमा को शादी के बाद भी इतनी जल्दी काम पे लगना था। चलो अच्छा है , इसी बहाने कहीं घूम के तो आई। भ…

Please find below the summary of The corner Shop. Do let me know for change, improvement anything you think. It is often said ‘The best ghost stories don’t have ghosts in them; rather, you see the result of its actions.’ For centuries readers have been attracted to the mysterious air surrounding ghosts and other supernatural beings. It is probably this sense of wonder and fear that makes ghost stories so addictive and hard to put down. An example of such a story is Cynthia Asquith’s The Corner Shop. The Corner Shop starts out as a happy story of a man, Peter Wood who discovers an antique shop filled with vintage trinkets run by two charming, young women. Upon browsing through its offerings, the man purchases a jade frog figurine at a throwaway price. Content with his purchase, Peter decides to make frequent visits to this lovely little shop. However, there is something sinister lurking behind the scenes. On the second visit to the store, Peter is in for an eerie surprise. Gone…

Th S.I. unit of energy is joul(J).
Let the power (p) of an electrical appliance = P watt
Let it is used for t seconds.
Then Electrical energy consumed (W) = P x t watt-second
i.e. W = Pt Watt-second
or W = Pt Joul (Joul is Mechanical unit equivalent of Watt-second)
In practice bigger unit like Watt-Hour (Wh) or Kilo Watt Hour (KWh) is used for Electrical energy consumption. Watt-Hour : It is the electrical unit consumed by an electrical appliance of P watt that was used for 1 hour. 1 w-hr = 1 watt x 1 hr
= 1 w x (60x60)second
=3600 watt-second
=3600 Joul
1 Whr =3600 J
Kilowatt-Hour: One kilowatt-hour is the electrical energy consumed by an electrical appliance of power rating 1 kw when it used for 1 hour.
1 KWhr = 1 kilowatt x 1 hr
= 1000 w x (60x60)second
=3.6x106 watt-second
=3.6x106 Joul
1 KWhr = 3.6x106 J
The electrical energy consumed in our houses or in industries are measured in KWhr . This is also called ! unit electrical unit consumed. The rate delared by gover…

Electrical Power: Rate of electrical energy supplied by a source e.g. a power station or an alternator or a dc battery etc is called electrical power.
∴ Power = Electrical Energy supplied / Time
if Power = P
Energy supplied = W
and Time = T
Then P = W / T
if W is in Joul
T in second
then unit of power will be Joul/Second (J/S); which is called watt.
∴ watt = j/s
∴Electrical Power, P=W/t=V.I=V2/R=I2.R
You are requested to suggest to make this chapter explanation better. So comment please.

Love Concern Humanity And Trust are the Eccentric Features of Mankind . Quoting examples from chapters : "The Last Leaf", Journey by Night", and "God Lives in Panch", Justify the statement . The main element which makes us differ from the rest are the qualities we possess.” Human nature is something which cannot be taught but which is self-existent. We, having an upper hand in the eco system, have something which other creatures lack. It is that object of our conscience which makes us good. Saying simply good is not enough because we are much more than being good. It is this positive quality in us, which makes us good. “The last leaf” by O Henry tells us the tale about unconditional concern which is not bounded by relationship but out of sheer care for one another. It is not only those people who are bounded by relationship care for one another but also those people who understand are not bounded but yet understand the pain of another. This chapter has taugh…

Ohm's Law: It can be defined as "The potential difference (P.D.) across a conductor is proportional to the current flowing through it provided that physical conditions remain constant." If V = Potential Difference (P.D.)
I= current
Then we can write V ∝ I
Or V= I. R
R= Constant and it is known as resistance of the conductor.
It also means that
V/I = Constant(R) , If all surrounding conditions are constant.
The resistance of a conductor depends on:
1. Length of the conductor.

2. Area of cross section of the conductor.

3. Type of material of the conductor.
It is because of the type of the material different conductors have different conductance. Copper is more good conductor than iron. Similarly silver is more good conductor than copper. Conductance of silver is slightly more than copper. As silver is costlier than the copper therefore we use copper instead of silver to ignore slight advantage of conductance. 4. Temperature of the conductor.
If the temperat…

By:R.K. Narayan
1. At nine-thirty, when he ought to have been shouting............Q ( A):    What would Swami usually do during prayer time at school? Q ( B ):    What,According to father,is the cause of Swami's headache? Q ( C ):    Is Swami honest in his words? When he give the excuse. Q ( D ):    What was usual activity of Swami mentioned in the first para. Q ( E ):    Why did Swami change his tactics while giving excuse in front of his father? Ans. A:    Swami used to shout during prayer time at school.
Back To TopAns.B :    According to father playing too much on weekends is the cause of Swami's headache.
Back To TopAns.C :    No Swamy is not honest in his word. Swamy changed his tactics as per the situation.
Back To TopAns. D :    Swami used to shout out in the School Prayer Hall during prayer time. This was the usual activity of Swami in the school. Perhaps he doesn't like the system of continuous teaching period after period. And also it may be that he us…

ABCD is a rhombus. DPR and CBR are straight lines.
Prove that:
Solution: DP.CR=DC.PR
Given ABCD is rhombus .
DPR and CBR are straight lines.
∴ AD||CR
we need to Prove : DP.CR=DC.PR
In &#x2206 ADP and &#x2206 PCR
We have :
&#x2220 APD = &#x2220 CPR
&#x2220 ADP = &#x2220 PRC
&#x2220 DAP = &#x2220 PCR
∴ &#x2206 ADP and &#x2206 PCR are similar triangle .
∴ we can write
∴DC .PR = DP.CR Proved

Suppose a Current I flows through a circuit as shown in the figure. The voltage across the resistance is V . The P.D. is the work done to move a charge Q from one point to another point, between which the p.d. is applied.
W = QV
But, Q= I.t

∴ W = VIt
Another energy equation By Ohm's Law:
V= I. R
Now, W = VIt
W = IR. It
∴ W = I2Rt

We can also write the energy equation in terms of voltage , resistance and time.
W = (V / R )2. Rt
∴ W = (V2t) / R

∴ W = Qv = VIt = I2Rt= (V2t) / R

- writer's name The man who is the speaker in this poem is a retired professor. He is known as Professor Seth. He addresses his student by telling him "Remember me? I am Professor Seth". The Professor has made a language error while talking to his student but he has used this awkward type of language throughout the poem . He continues by reminding his student that once he used to teach him geography. While talking to him about schooldays he straight goes into the story of his own life. He is retired now but he is healthy and his wife died some years ago. His children are doing well and they are well settled in their life. So the Professor boasts about his children's status. One is a Sales manager and the other is a Bank manager. They both have cars. He also criticised his other children like his third son who are not doing well. He criticises him by telling this clause that "family must have a black sheep". He then boasts about his two daughters…

By - Douglas Malloch The poem " Be the best" teaches us a very important lesson of our life. The title is sufficient for anyone to understand the concept of the poem. The poet Douglas Malloch wants to tell us that whatever you want to be or whatever you can be ,just be the best one in that field. The poet starts the poem by giving examples of nature. He says if you are not able to be pine on the top of the hill then just try to be the scrub which are little elevated grasses but you must be the best scrub by the side of the stream. For example if you can't be the boss of an office then just you try to be a worker but be the best worker of that office. The poet again teaches us to be the bush if we can't be strong like a tree. If also we can't be a bush then a bit of little grass. Douglas Malloch says us to be the happiest . He gives example of music. He says that if we can't be the good music then be the cheerful bass in the lake. All of us cannot be …

Emf: Emf is defined as work done per unit charge in taking a positive charge through the complete circuit ( the circuit outside the source (cell) and inside of the source. emf is represented by greek letter ε
If W is the work done when a test charge of q0 is taken through the complete circuit of a cell with a external resistance or lamp etc. Then emf of the cell is : ε=W/q0
For detail watch the video.
If you have any confusion then ask below in the comment box.

मैने कल रात एक सपना देखा, कि मैं एक बादल था। मैं वाष्प से बना था और मुझ में पानी था। मैं पानी से बोझिल था, और बौछार करने के लिए इंतजार कर रहा था । मै अपने आपको किसी भी आकार भें ढाल सकता था । थोड़ी ही देर में मै कुत्ता बन गया जो मुंह मैं एक हड्डी लिया हुआ था । बच्चे मेरी तरफ उंगली उठाकर कह रहे थे कि देखो बादल कुत्ता जैसा दिखता है। दूसरे दिन मैं अपने आपको उपयोगी बना दिया। मैं ऐसी जगह गया जहां पर लोग सूखे से फैली भुखमरी से मर रहे थे । मैने वहां के लोगों में क्रोध और दुःख दोनों देखा। लोग मेरे इंतजार में प्रार्थना कर रहे थे। थोड़ी ही देर में मैं वहां छा गया और अपने आपको पूरी तरह खोल दिया | वहां की जमीन को मैने बारिश से सराबोर कर दिया । लोग बहुत खुश हो गए। वो ऊपरवाले की प्रार्थना करने लगे और खुशी से नृत्य करने लगे । दूसरे दिन मैं ऐसी जगह था , जहां चारो तरफ पानी ही पानी था । लोगों को मैं डूबते हुए देख रहा था । मै सोचा शायद मेरे मां बाप ने ऐसा किया था । क्योंकि के इन मनुष्यों के प्रकृति के विरुद्ध कार्यो से बहुत नाराज थे। मै चुपचाप उन्हें डूबते हुए और उन्हें उनके पापों के कारण भु…

Resistance: Resistance of a conductor is the opposition offered by the conductor to the flow of current through it. Resistances are of two type fixed resistance and variable resistance. Reason of resistance: The resistance is due to collision of moving electrons while moving from negative terminal to positive terminal. In this process when electrons collide with positive ions , few electrons drift away and do not reach to the positive terminal. Because of this drifted electrons the conductance of the conductor decreases and therefore resistance results in this process. Conductance = 1 / resistanceRt=R0 ( 1+ α t) ohm.
where t = Tt - T 0
Where Rt = Resistance at temperature t 0C
R0 = Resistance at temperature 00C
α = temperature Co-efficient of resistance of a particular conductor.
Temperature Co-efficients (α)Conductor MaterialTemp. Co-efficentUnitCopper4.041 x 10-3Ohm-mAluminium4.308 x 10-3Ohm-mResistance formula from the relation of potential difference and current is given below.

Potential Difference: Potential difference between two terminal of a conductor is the work done while carrying unit positive charge from one terminal to the other terminal.

Unit of the potential difference is volt.
V = W / Q
or 1 V = 1JC-1
1 Volt is equal to 1 Jouls/coulomb.
and W = QV
Above equations should be memorized
Potential difference is measured by voltmeter. If the VA and VB be the potential of the two end of a conductor then we can write
VA - VB = W /Q

प्राकृतिक आपदा पर निबंध प्रकृति द्वारा जो आपदा आती है वह बहुत ही भाया वह होती है । इसका आकार बहुत बड़ा होता है। अनेक आपदाओं में से बाढ़ और भूकंप बहुत बार होता रहता है। हाल ही में चेन्नई में बाढ़ आया जो दक्षिण भारत को अस्तव्यस्त करके रख दिया । इसका प्रभाव मानव जीवन पर इस तरह हुआ कि मानो जीवन रुक गया है। घरों का पहला तल्ला पूरा पानी में डूब गया । ट्रेन बस वायुसेवा टेलीफोन ए टी एम बैकिंग आदि एकदम बन्द हो गया था । सबसे भयानक है टेलीफोन सेवा का बन्द होना। क्योंकि सूचनाए मिलना बन्य हो जाती है। किसी तरह सरकार की सहायता से बहुत लोगों की जान बचाई जा सकी । फिर भी अधिक लोगों की मृत्यु हो गई । इन सभी प्राकृतिक आपदाओं से हमें सीखना होगा कि किस प्रकार प्रकृति पर बिना कारण के बोझना डालें। नहीं तो प्रकृति का असंतुलन मनुष्य पर बहुत भारी पड़ेगा । हमें प्रकृति का संतुलन बनाए रखने के उपाय सोचने चाहिए । ऐसे कार्यो को नहीं करना चाहिए जिससे प्रकृति गुस्से में आए और बड़ा सर्वनाश कर जाए ।

Current (I) : Current can be defined as rate of flowing of charge (Q).
I= Q/t
where Q= Charge in coulumb
I = current in Ampere
t= Time in second.
1 Ampere is the charge flowing through a conductor in 1 second.
Q= I x T Amp-Sec
In an ionised electrolyte charged ions flow from one plate to another. For example negative ions flow from cathode to anode and positive ions flow from anode to cathode. charge of 1 e = 1.6x10-19 Coulomb
or 6.25x1018 electrons= 1 coulomb