Interference of Light

When two light waves of similar frequency having a zero or constant phase difference propagate in a medium simultaneously in the same direction, then due to their superposition maximum intensity is obtained at few points and minimum intensity at other few points.

This phenomena of redistribution of energy due to superposition of waves is called interference of light waves.

The interference taking place at points of maximum intensity is called constructive interference.

The interference taking place at points of minimum intensity is destructive interference.

Fringe Width

The distance between the centres of two consecutive bright or dark fringes is called the fringe width.

The angular fringe width is given by θ = λ / d.

where λ is the wavelength of light d is the distance between two coherent sources.

`The Tale of Custard the Dragon’ is a whimsical fantasy. Belinda lives alone in her house with four pets, a dog, a cat, a mouse and a dragon named Custard. All other dwellers of the house except Custard, pride themselves on their fearlessness. They mock poor Custard for his timidity. However, when the real danger comes all others run away in a panic except Custard. Only Custard fights ferociously and swallows the pirate. The poem ends ironically. After the danger is past, everyone begins to boast again about their courage. Ironically, Custard who fought like a hero against the pirate agrees that everyone else is braver than he is. So, appearances may be deceptive. And even your merit and real value may not be recognised by your unwilling rivals.

Young’s double slit experiment (YDSE)

The Young’s experiment shows that matter and energy can display both wave and particle characteristics.

Purpose of double slit experiment is as follows:-

1. In order to prove the wave nature of light.
2. To explain the phenomenon of interference.

Two coherent sources of light were taken in order to maintain the 0 or constant phase difference between the sources of light.

• Experimental set-up1:-
  • Young took an ordinary source of light(S) such as light bulb.
  • The light was made to pass through a very small slit S (which was comparable with the wavelength of light).
  • The light coming from Source S was made to pass through two small slits S₁ and S₂ which were separated by a very small distance d.
  • One screen was kept in front of these 2 sources.

Observation1:-

• He observed alternate dark and light bands were formed on the screen.

Setup 2:-

• Now he took 2 light bulbs i.e. 2 non coherent sources of light and placed a screen in front of them.

Observation 2:-

• He observed there were no alternate bands of light formed on the screen.
• Conclusion:-
• When coherent sources of light were taken then the phenomenon of interference is taking place.
• When non-coherent sources were taken phenomenon of interference was not taking place.
• The source S illuminated the sources S₁ and S₂ as a result the light from S₁ and S₂ become coherent.
• S was the source of bothS₁ and S_2, therefore if there is any change in the phase of the source there will be change in the both sources also.
• Therefore both S₁ and S₂ will be always in phase with each other.

K=-15\4

X ke place pe -1/2 daal do aur equate kro aa jayega

Putting x = (-1/2) in 3x² + 2kx - 3 = 0,

or

Given : If  is a solution of the quadratic equation .

To find : The value of k ?

Solution :

To get the value of k substitute the value of x in the equation,

Equation 

Put ,

Therefore, The value of k is   or  

Huygens Principle

• Huygens principle states that each point of a wavefront is the source of secondary wavelets (small waves) which spread in all directions with the speed of the wave.
• The new wavefront is formed by drawing a line tangent to all the wavelets.

 

For example:-

• If a stone is thrown in the river,waves will be formed surrounding that point.
• These waves look like concentric circles and they are known aswavefronts.
• The wavefronts gradually spread in all the directions.
• When the locus of all the waves is joined which are in the same phase, it will be the same as a sphere, and are known as Primary wavefront.
• Secondary wavefront are formed fromeach point on the Primary wavefront.
• The common tangential line that envelopes these secondary wavefronts will further give rise to other secondarywavefronts.
• All wavefronts will gradually fade after some time.

• Conclusion: - According to Huygens principle, every point on a wavefront give rise to secondary wavelets which spread out in all the directions with the speed of a wave.

What s

Why on whatsapp we can call your parents right

• Don't post personal information, mobile numbers and other details.
• Don't use this platform for chatting, social networking and making friends. This platform is meant only for asking subject specific and study related questions.
• Be nice and polite and avoid rude and abusive language. Avoid inappropriate language and attention, vulgar terms and anything sexually suggestive. Avoid harassment and bullying.
• Ask specific question which are clear and concise.

If content is found in violation, the user posting this content will be banned for 30 days from using Homework help section. Suspended users will receive error while adding question or answer. Question comments will be disabled. Read community guidelines at https://mycbseguide.com/community-guidelines.html

0

What

0

Great Wall of China The Great Wall of China is the longest in the world and has a main-line length of 3,460 km (2,150 miles - nearly three times the length of Britain - plus 3,530 km (2,193 miles) of branches and spurs.Great Wall of China The Great Wall of China is the longest in the world and has a main-line length of 3,460 km (2,150 miles - nearly three times the length of Britain - plus 3,530 km (2,193 miles) of branches and spurs.accepts the data, stores data, processes the data and then produces a result. It can process the input data to give the desired output according to the instructions we give. A computer is made up of Hardware and Software devices. The parts of a computer are divided into input and output devices.A computer is an electronic device that accepts the data, stores data, processes the data and then produces a result. It can process the input data to give the desired output according to the instructions we give. A computer is made up of Hardware and Software devices. The parts of a computer are divided into input and output devices.https://play.google.com/store/apps/details?id=com.mobisystems.msdict.embedded.wireless.oxford.dictionaryofenglishhttps://realfantasysports.in/dream-team/?id=0&redir=/live/gallery/&hash=collection:real-poker-girl:/shoots/real-poker-girl/15_preview.jpgmeet.google.com/tjd-yeza-szqदरवाज़े सै हम बाहर आेर अंदर आ सकते हैंदरवाज़ेफूलफूलोंRotiya bahut hi achi bani1.नमस्ते अध्यापक जी सुप्रभात अध्यापक जी आप कैसे है अध्यापक जीPeople walk on their feet. The buses run on the sea. They wear their hats on their heads Boats travel in streets. People pay for what they get.Ans No.1 In Topsy-turvy land children go to school at night. Ans No.2 In the poem, boats travel in the streets. They should travel on the sea.listensनमस्ते अध्यापक जी सुप्रभात अध्यापक जी आप कैसे है अध्यापक जीLet’s Talk (i)Renu is a naughty girl. (ii) Her room is always untidy. (iii)Her mother advises her to clean it. (iv) She never listens to her mother. (v)What kind of a child are you?Can you tell of some things that go Topsy-turvy at home and there is disorder? Ans.Yes, things go topsy-turvy, when we have a function at home, and we put things anywhere to make space Or when I and my friends play atबहुत मज़ा अध्यापक जी।।People walk on their feet. The buses run on the sea. They wear their hats on their heads Boats travel in streets. People pay for what they get.01-12-2020Search Search Quizzes Search Search Create A Quiz Take Quizzes Products ProProfs Quizzes Advertisement close Please wait 6 / 20 30 % Which noun below is a collective noun: Women Duck Family Children Advertisement Advertisement Your Score: 10/100 All (20) Unanswered (15) Answered (5) George Washington is an example of a/an: 93% got this correct Discuss Government is an example of a/an: 53% got this correct Discuss The plural of father-in-law is: 72% got this correct Cities' is an example of a: 57% got this correct Discuss 'Boys' is an example of a: 79% got this correct View All Related Quizzes A Plural Noun Test Quiz! English Grammar Quiz: Uncountable Noun! Regular And Irregular Plural Nouns Quiz! French - Masculine Or Feminine Noun? Gender Of Nouns! Trivia Questions Quiz Top Scores Rank Name Score 1 Ahmed Youssef 100 ( 1m 15s ) 2 Ahmed Fuad 100 ( 1m 19s ) 3 Nandu 100 ( 1m 20s ) 4 Avram Cristian 100 ( 1m 21s ) 5 Salma 100 ( 1m 21s ) AdvertisementSearch Search Quizzes Search Search Create A Quiz Take Quizzes Products ProProfs Quizzes Advertisement close Please wait 6 / 20 30 % Which noun below is a collective noun: Women Duck Family Children Advertisement Advertisement Your Score: 10/100 All (20) Unanswered (15) Answered (5) George Washington is an example of a/an: 93% got this correct Discuss Government is an example of a/an: 53% got this correct Discuss The plural of father-in-law is: 72% got this correct Cities' is an example of a: 57% got this correct Discuss 'Boys' is an example of a: 79% got this correct View All Related Quizzes A Plural Noun Test Quiz! English Grammar Quiz: Uncountable Noun! Regular And Irregular Plural Nouns Quiz! French - Masculine Or Feminine Noun? Gender Of Nouns! Trivia Questions Quiz Top Scores Rank Name Score 1 Ahmed Youssef 100 ( 1m 15s ) 2 Ahmed Fuad 100 ( 1m 19s ) 3 Nandu 100 ( 1m 20s ) 4 Avram Cristian 100 ( 1m 21s ) 5 Salma 100 ( 1m 21s ) AdvertisementSearch Search Quizzes Search Search Create A Quiz Take Quizzes Products ProProfs Quizzes Advertisement close Please wait 6 / 20 30 % Which noun below is a collective noun: Women Duck Family Children Advertisement Advertisement Your Score: 10/100 All (20) Unanswered (15) Answered (5) George Washington is an example of a/an: 93% got this correct Discuss Government is an example of a/an: 53% got this correct Discuss The plural of father-in-law is: 72% got this correct Cities' is an example of a: 57% got this correct Discuss 'Boys' is an example of a: 79% got this correct View All Related Quizzes A Plural Noun Test Quiz! English Grammar Quiz: Uncountable Noun! Regular And Irregular Plural Nouns Quiz! French - Masculine Or Feminine Noun? Gender Of Nouns! Trivia Questions Quiz Top Scores Rank Name Score 1 Ahmed Youssef 100 ( 1m 15s ) 2 Ahmed Fuad 100 ( 1m 19s ) 3 Nandu 100 ( 1m 20s ) 4 Avram Cristian 100 ( 1m 21s ) 5 Salma 100 ( 1m 21s ) AdvertisementMaths subject PT- 1 syllabus 1. The fish tale 2. Shape and Angles 3. How many Squares 4. Parts and WholesGood afternoon ma'am

Nooo

A n s w e r
Water is colorless and transparent because ALL except a tiny bit of blue (for pure water) are reflected back. Since water reflects all colors together it looks colorless.

Cpu- central processing unit

The full form of CPU is the Central Processing Unit. The CPU socket is a particular section where the CPU is mounted inside the motherboard to perform other outputs and inputs of the system. The CPU’s known as the brain of a computer. It performs all the basic logical and arithmetic operations activities and transmits the commands and programs of the computer. The term CPU is normally used to refer to a processor that consists of the arithmetical logical unit

and control unit.

CPU = ALU + CU

Where

ALU – Arithmetical Logical Unit

CU – control unit

Kamla kaul nehru

Kamala Kaul Nehru

Shri Jawaharlal Nehru

Kamala kaul Nehru

A n s w e r : the wife of Jawaharlal Nehru was Kamala Kaul Nehru 
Kamala Kaul Nehru was an Indian independence activist and the wife of Jawaharlal Nehru. Her daughter Indira also served later as Prime Minister of India

Rakesh Sharma

Rakesh Sharma

Rakesh Sharma

Rakesh sharma

Rakesh Sharm

The first Indian to fly into space, Rakesh Sharma was born on January 13, 1949 in Patiala, Punjab. He was a squadron leader with the Indian Air Force, when he flew into space in 1984 as part of a joint programme between the Indian Space Research Organisation (ISRO) and the Soviet Intercosmos space program. He spent eight days in space on board the Salyut 7 space station. He joined two other Soviet cosmonauts aboard the Soyuz T-11 spacecraft which blasted off on April 2, 1984.

Issac Newton

Issac Newton

ISSAC NEWTON

Issac Newton discovered gravity

 Isaac Newton

Sir Isaac Newton was an English mathematician and mathematician and physicist who lived from 1642-1727. The legend is that Newton discovered Gravity when he saw a falling apple while thinking about the forces of nature

What is net frame work

Wright brother

Wilbur and orlive wright

On December 17, 1903, Wilbur and Orville Wright made four brief flights at Kitty Hawk with their first powered aircraft. The Wright brothers had invented the first successful airplane.

Yuri gagrin

Yuri gagrin

You are right Gaurav seth

A n s w e r 
Yuri Gagarin was the first person to fly in space. His flight, on April 12, 1961, lasted 108 minutes as he circled the Earth for a little more than one orbit in the Soviet Union's Vostok spacecraft

Helll ritesh bro i am seraj

measurement of length in one direction. Examples: width, depth and height are dimensions. ... a square has two dimensions (2D), and a cube has three dimensions (3D). In Physics it can also mean any physical measurement such as length, time, mass, etc.

• January 1915 — Mahatma Gandhi returned to India from South Africa
• 1919 — Gandhiji launched satyagraha against the Rowlatt Act
• 13 April 1919 — Jallianwala Bagh incident
• March 1919 — Khilafat Committee formed
• September 1920 — Gandhiji convinced Congress for a non-cooperation movement
• December 1920 — Non-Cooperation program was adopted by Congress in Nagpur
• January 1921 — Non-Cooperation-Khilafat Movement began
• October 1920 — Oudh Kisan Sabha 6 January 1921 Police firing at peasants in Rae Bareli
• 1920 — The militant guerrilla movement spread in Gudem Hills, Andhra Pradesh
• 1922 — Chauri Chaura violence
• 11 February 1922 — Gandhiji decided to withdraw the Non-Cooperation Movement
• 1928 — “Go Back Simon” movement
• Nov 1930 -Jan 1931 — First Round Table Conference
• Sept-Dec 1931 — Second Round Table Conference
• Nov -Dec 1932 — Third Round Table Conference
• December 1929 — The “Purna Swaraj” was formalized
• 26 January 1930 — Declared to be celebrated as the Independence Day but got very little attention
• 31 January 1930 — Gandhiji sent a letter of Viceroy Irwin stating 11 demands
• 12 March 1930 — Salt March or Dandi March or Dandi Satyagraha or Civil Disobedience Movement started
• 6 April 1930 — Salt March ended
• April 1930 — Abdul Ghaffar Khan got arrested
• May 1930 — Mahatma Gandhi got arrested
• 5 March 1931 — Gandhi-Irwin Pact
• 23 March 1931 — Bhagat Singh, Rajguru and Sukhdev were sentenced to death
• December 1931 — Gandhiji went to London for a conference but returned disappointed
• 26 September 1932 — Poona Pact
• Jan 1932 — Civil Disobedience Movement started again
• 1920 — Indian Industrial and Commercial Congress
• 1927 — Federation of the Indian Chamber of Commerce and Industries (FICCI)
• 1906 — Muslim League established
• 1928 — Death of Lala Lajpat Rai
• 1935 — The government of India Act
• 8 August 1942 — Quit India movement launched
• August 1925 — Kakori Train Conspiracy Case

Ch

This story is about the witty secret agent Ausable. He was with a writer friend Fowler. They planned to spend time in the evening. Then Fowler realized that he is exactly the opposite of what he had imagined about him. Ausable told Fowler that he had been thinking wrong and very soon he would be looking at a very important report which would change the country’s future. Then both went to his room. But, when they enter the room another guy Max with a gun was standing in the room. He asked them to be comfortable until the reports related to missiles arrived. This was really an adventurous experience for the Fowler while meeting with a secret agent. Meanwhile, Ausable started with a story about a hypothetical balcony below the window of his room. While this talk was going on, someone was continuously knocking at the door. Ausable said that the police were at the door came to check him and his room on a regular basis. Max, pointing his gun towards both of them, said that he would be waiting in the balcony and during this time Ausable should send away the police otherwise he would shoot them.

It usefull and u gyu recite very well???

About secret agent Ausable
Ausable was a secret agent. But he did not look like that. Fowler felt sad that Ausable did not look like a secret agent. Ausable had a room on the sixtli and top floor of a French hotel.

Ausable and Fowler together
Ausable was very fat. He spoke French and German. But he had the American accent. Ausable told Fowler that he would be sad. He (Ausable) didn’t look like a spy. Fowler was a writer. He had expected to see strange figures in the night. He also expected to hear the sound of pistols or about drugs in the wine. But it was never so in his case. As against this, Ausable told him that he had no beautiful girls around him. He might feel bored in his company. Saying so Ausable opened the door of his little room for Fowler.f

Max seen with a pistol
After a few moments, Ausable told Fowler that he would see an important paper. Several men and women were after that. This paper could change the course of history. Ausable closed the door. He switched on the light. Fowler saw a man with a small automatic pistol across the room. It was Max. Seeing him Ausable said that he was shocked to see him there. He thought that he was in Berlin.

Ausable confuses Max with balcony
Max was thin and not tall. He looked like a fox. Max told Ausable that he came there for something. It was to take the report about some missiles from him. Ausable sat into an armchair. He told him that he would complain to the management. It would be that someone had entered his room through an ordinary window in the balcony. The balcony should be closed at once. Max reacted saying that he didn’t enter the room from the balcony. He had a passkey. Ausable told him that the balcony was of the next room.

Talk about the report
Max looked at Fowler. He asked him to sit down. Ausable asked Max how he had learned about the report. Max told Ausable he wished he knew how Ausable’s men had obtained the report. He hopqd to get the report back that night. Then there was a knocking at the door.

Deception through police
Fowler jumped at this sudden knocking. Ausable smiled. He told that that was the police. He had told the police about the important paper. It needed extra protection. So the police was there to make everything all right.

Max in the non-existing ‘balcony’
Hearing this, Max got nervous. Ausable asked Max what he would do. If Ausable did not answer the door, the police would enter anyway. The door was unlocked. The police might shoot also as the papers were very important. Max’s face was black with anger. He opened the window and put his leg out into the night. He asked Ausable to send the police back. He would go and wait on the balcony. He also warned that he would shoot and take his chance. (There was no balcony.)

Max drops down
The knocking at the door became louder. Max had his gun cover Ausable and Fowler. He stood there catching the doorframe with his other free hand to support himself. Then he moved his other leg up and over the window sill. The doorknob turned. Max freed himself and dropped to the ‘balcony’. He shrieked sharply. It means he had fallen on the ground.

Waiter’s service inside
The door opened. A waiter stood there with a tray, a bottle and two glasses. He set the tray at the table. He uncorked the bottle and left the room.

How Ausable proves a real secret agent
This amazed Fowler. He asked Ausable about the police. Ausable told him that there was never any police. Fowler asked about the man on the balcony, ie, Max. Ausable told him that he won’t return. In this manner Ausable had outsmarted Max.

• January 1915 — Mahatma Gandhi returned to India from South Africa
• 1919 — Gandhiji launched satyagraha against the Rowlatt Act
• 13 April 1919 — Jallianwala Bagh incident
• March 1919 — Khilafat Committee formed
• September 1920 — Gandhiji convinced Congress for a non-cooperation movement
• December 1920 — Non-Cooperation program was adopted by Congress in Nagpur
• January 1921 — Non-Cooperation-Khilafat Movement began
• October 1920 — Oudh Kisan Sabha 6 January 1921 Police firing at peasants in Rae Bareli
• 1920 — The militant guerrilla movement spread in Gudem Hills, Andhra Pradesh
• 1922 — Chauri Chaura violence
• 11 February 1922 — Gandhiji decided to withdraw the Non-Cooperation Movement
• 1928 — “Go Back Simon” movement
• Nov 1930 -Jan 1931 — First Round Table Conference
• Sept-Dec 1931 — Second Round Table Conference
• Nov -Dec 1932 — Third Round Table Conference
• December 1929 — The “Purna Swaraj” was formalized
• 26 January 1930 — Declared to be celebrated as the Independence Day but got very little attention
• 31 January 1930 — Gandhiji sent a letter of Viceroy Irwin stating 11 demands
• 12 March 1930 — Salt March or Dandi March or Dandi Satyagraha or Civil Disobedience Movement started
• 6 April 1930 — Salt March ended
• April 1930 — Abdul Ghaffar Khan got arrested
• May 1930 — Mahatma Gandhi got arrested
• 5 March 1931 — Gandhi-Irwin Pact
• 23 March 1931 — Bhagat Singh, Rajguru and Sukhdev were sentenced to death
• December 1931 — Gandhiji went to London for a conference but returned disappointed
• 26 September 1932 — Poona Pact
• Jan 1932 — Civil Disobedience Movement started again
• 1920 — Indian Industrial and Commercial Congress
• 1927 — Federation of the Indian Chamber of Commerce and Industries (FICCI)
• 1906 — Muslim League established
• 1928 — Death of Lala Lajpat Rai
• 1935 — The government of India Act
• 8 August 1942 — Quit India movement launched
• August 1925 — Kakori Train Conspiracy Case

Thnq soo much

Let the cost price of one chair be Rs. x and that of one table be Rs. y. Profit on chair = 25%.

∴ Selling price of one chair 

Profit on a table = 10%

∴ Selling price of one table = 

According to the given condition, we have

If profit on a chair is 10% and on a table is 25%, then total selling price is Rs. 1535.


 

Subtracting equation (ii) from equation (i), we get
3x - 3y = -300 ⇒ x - y = -100
Adding equation (ii) and (i), we get
47x + 47y = 61100 ⇒ x + y = 1300
Thus, we have following equations
x - y = -100    ...(iii)
x + y = 1300    ...(iv)
From (iii), we have
x - y = - i 00
⇒    x = y - 100    ...(v)
Substituting the value of x in (iv), we get
x + y = 1300
⇒ y - 100 + y - 1300
2y - 100 = 1300
⇒    2y - 1400 ⇒ y = 700
Substituting the value of y in (v), we get
x = y - 100
⇒ x = 700 - 100 = 600
Hence, cost price of one chair = Rs. 600 and cost price of one table = Rs. 700

Self-esteem refers to a person's beliefs about their own worth and value. It also has to do with the feelings people experience that follow from their sense of worthiness or unworthiness. Self-esteem is important because it heavily influences people's choices and decisions.

The Combining of two atoms are called covalent bonds

Nice to meet you both

???bbye... baad me aati hu?

Hn shayad ?jyada padh rhe h sbb?

Ruko msg krti hu???

Baat nhi hue h bhot time se ?Diwali pe hi hue thi?.. Us time achhi thi ?

bss chal rii h??Ohh.. phir half yearly kab honge ab? ?

Half yearly hue the... Unit to ek bar online hi hue the ?

A head of Gram Panchayat

A Gram Panchayat consists of a village or two to three villages together, which are divided into wards. One candidate stands for election from each ward. The successful candidate from all the wards form the panch. The head of the panchas is called the sarpanch who is selected through voting among the panchas.

In situ Conservation	Ex situ Conservation
It means the conservation of biodiversity in their natural habitats itself.	It means the conservation of biological diversity outside their natural areas
Protected areas are the sanctuaries and national parks.	Artificial conditions are created to make their habitat almost like a natural habitat.
It aims to enable biodiversity to maintain itself within the context of the ecosystem.	It involves the maintenance of genetic variation (Genetic Conservation) away from its original location.
Establish a protected area network, with appropriate management practices, corridors to link fragments restore degraded habitats within and outside.	Established botanical and zoological gardens, conservation stands; banks of germplasm, pollen, seed, seedling, tissue culture, gene, and DNA, etc.
It involves the reduction of biotic pressure rehabilitation	It identifies and rehabilitates threatened species; launched augmentation, reintroduction, or introduction programs.
It helps in the multiplication of the species through the process of evolution and adaptation.	This method will enhance the probability of reproductive success for endangered species.
It provides greater mobility to the animal species because of the large habitat area.	It provides less mobility to the organism because of the small habitat area.
Example- National parks, biosphere reserves, parks, sanctuaries.	Example- Zoo, aquarium, seed banks, botanical gardens, etc.