Introduction of Number System

Chapter -01 NUMBER SYSTEM

NATURAL NUMBERS (N) - Counting numbers are called natural numbers.

The collection of natural numbers is denoted by N and is written as N= (1, 2, 3, 4, 5, 6, ...)

REMARKS

(1) The least natural number is 1.

(2) There are infinitely many natural numbers.

WHOLE NUMBERS All natural numbers together with 0 form the collection W of all whole numbers, written as W=10, 1, 2, 3, 4, 5,...).

REMARKS

(i) The least whole number is 0.

(ii) There are infinitely many whole numbers.

(iii) Every natural number is a whole number.

(iv) All whole numbers are not natural numbers, as O is a whole number which is not a natural number.

INTEGERS All natural numbers, O and negatives of natural numbers form the collection of all integers. It is represented by Z after the German word 'zahlen' meaning 'to count'. Thus, we write Z=1,-5,-4,-3,-2,-1, 0, 1, 2, 3, 4, 5, ...).

REMARKS

(1) 0 is neither negative nor positive.

(ii) There are infinitely many integers.

(iii) Every natural number is an integer.

(iv) Every whole number is an integer.

RATIONAL NUMBERS The numbers of the form p/q where p and q are integers and q is not equal to 0 are known as rational numbers. The collection of rational numbers is denoted by Q and is written as

Q= P 1≠0}. 19: p. q are integers, q ≠ 0)

‘Rational’ comes from the word ‘ratio’ and Q comes from the word ‘quotient’.

Thus, ¼, 3/2, 11/79, - 2001/2002 etc., are all rational numbers.

REMARKS

(i) There are infinitely many rational numbers.

(ii) There is no least or greatest rational number.

(iii) 0 is a rational number, since we can write, 0 = 0/1

(iv) Every natural number is a rational number since we can write, 1 = 1/1 2 = 2/1 3 = 3/1 etc.

(v) Every integer is a rational number since an integer a can be written a/1 . – 31 = - 31/1 0 = 0/1 and 79 = 79/1

Hence, rational numbers include natural numbers, whole numbers and integers.

SIMPLEST FORM OF A RATIONAL NUMBER A rational number p/q is said to be in its simplest form, if p and q are integers having no common factor other than 1 (that is, p and g are co-primes) and q not equal to 0 .

Test

Enter your name

World Wide Web

1. What is E-Commerce?

Ans. E-commerce refers to the buying and selling of goods and services over the internet. It involves online transactions, digital payments, and the exchange of data to facilitate business activities. E-commerce can take various forms, such as business-to-consumer (B2C), business-to-business (B2B), and consumer-to-consumer (C2C) transactions.

2. What are protocols? Give example.

Ans. Protocols are sets of rules and standards that govern communication, data exchange, and interactions between devices, systems, and networks.

Examples of protocols include:

1. HTTP (Hypertext Transfer Protocol) - used for transferring data over the internet.

2. FTP (File Transfer Protocol) - used for transferring files over the internet.

3. TCP/IP (Transmission Control Protocol/Internet Protocol) - used for routing data packets over the internet.

4. SMTP (Simple Mail Transfer Protocol) - used for sending and receiving email.

5. HTTPS (Hypertext Transfer Protocol Secure) - a secure version of HTTP used for encrypted data transfer.

3. What are the different components of the web?

Ans. The different components of the web include:

1. *Hardware*: Servers, routers, modems, and client devices (computers, smartphones, etc.).

2. *Software*: Web browsers, web servers, and programming languages.

3. *Network*: Internet Service Providers (ISPs), Internet backbone, and local area networks (LANs).

4. *Protocols*: HTTP, FTP, TCP/IP, and other communication protocols.

5. *Data*: Text, images, audio, video, and other types of digital content.

6. *Web pages*: HTML documents, CSS stylesheets, and JavaScript files.

7. *Databases*: Storage systems for dynamic web content.

8. *Web applications*: Dynamic websites, online services, and web-based software.

4. Explain in short any three applications of the web ?

Ans.Here are three applications of waves:

1. *Communication*: Radio waves are used to transmit information wirelessly, enabling communication through devices like radios, mobile phones, and satellite TVs.

2. *Navigation*: GPS technology relies on radio waves to provide location information and navigate through unfamiliar territories.

3. *Medical Imaging*: Ultrasound waves are used in medical imaging to create images of internal organs and tissues, helping diagnose medical conditions.

5. What is web hosting?

Ans. Web hosting is a service that allows individuals and organizations to host their websites on the internet. It involves storing website files, data, and content on a server, which is then accessible to the public via the internet.

Animation in Flash

1. What is Flash?

Ans. Adobe Flash, it's a multimedia software platform used to create interactive, animated, and dynamic content for web, mobile, and desktop applications.

2. What is Stage ?

Ans. Stage is the main workspace area where you create and design your Flash content, such as animations, graphics, and interactive elements.

3. What is Timeline in flash?

Ans.In Adobe Flash, a Timeline is a visual representation of the sequence of events and animations in a Flash movie. It displays the layers, frames, and tweens that make up the animation, allowing you to organize, edit, and control the timing and pacing of your animation.

4. What do you understand by Animation?

Ans. Animation refers to the process of creating the illusion of movement and change by displaying a sequence of static images or frames in rapid succession. This can be done using various techniques, such as traditional hand-drawn animation, computer-generated imagery (CGI), or stop-motion animation.

5. What is Keyframe?

Ans. In animation, a Keyframe is a specific frame in a sequence that defines a key moment or pose in the animation. It's a frame where a significant change or action occurs, and it serves as a reference point for the animation software to create the motion between keyframes.

Using Photoshop

Que1 :- What is the use of liquify tool?

Ans :- The Liquify tool is a powerful and creative tool that helps you manipulate images. It allows you to stretch, squeeze, push, and pull parts of an image to create unique and artistic effects.

You can use the Liquify tool to deform images, such as changing facial features, enlarging eyes, or reshaping bodies. It's a great tool for creating creative and artistic effects in your images.

Que 2:- What is Forward Wrap Tool ?

Ans. The Forward Warp tool is used to push pixels forward, creating a bulging or warping effect. It's often used to create subtle or dramatic changes in an image, such as changing the shape of a face or object.

Que 3. Define the construction tool. 

Ans. These tools allow users to create and edit vector shapes, paths, and selections, which can be used for a variety of tasks, such as creating logos, icons, and graphics, or making selections and masks in an image.

Que 4. What is a twirling Tool ?

Ans. In Photoshop, Twirling is a feature of the Liquify filter that allows you to rotate or swirl a portion of an image around a central point. It's a creative tool that can be used to add a sense of movement or energy to an image.

Que 5: How blur tool work ?

Ans. The Blur Tool is a retouching tool used to soften or blur specific areas of an image. It works by reducing the clarity and definition of the selected area, creating a subtle, natural-looking blur effect.

Que 6. What is Sharpen Tool ?

Ans. The Sharpen Tool is a retouching tool used to increase the clarity and definition of specific areas of an image. It works by accentuating the edges and details of the selected area, making it appear sharper and more defined.

Que 7. What is smudge tool ?

Ans. The Smudge Tool is a painting tool used to create a smudged or smeared effect on an image. It works by simulating the effect of dragging a wet brush or finger across the image, blending and merging colors together to create a soft, smudged appearance.

Que 8. What is Sponge tool ?

Ans. The Sponge Tool is a retouching tool used to subtly adjust the saturation and desaturation of specific areas of an image. It can be used to add or remove color from an image, creating a more natural or artistic look.

Anchor tag and IMG tag

 

Questions 1. Define <img> tag and src attribute.

Answer :- The <img> tag is used to embed an image in an HTML page.

Images are not technically inserted into a web page; images are linked to web pages. The <img> tag creates a holding space for the referenced image.

The <img> tag has two required attributes:

• src - Specifies the path to the image

• alt - Specifies an alternate text for the image, if the image for some reason cannot be displayed

Example:- <img src=”img_girl.jpg” alt=”Girl in a jacket” width=”500” height=”600”>

Questions 2:- Differences between gif and jpeg .

Answer:- The difference between GIF and JPEG is that GIF is a better choice for computer graphics with limited color palettes (like logos, simple cartoons, or line art), while JPEG is a better format for photographs and colorful images, and it also looks good when printed.

The extension of gif is .gif

The extension of jpeg is .jpeg

Questions3:- what is hyperlink?

Answer:- A hyperlink can be thought of as an interface that links a source to a target. Clicking the hyperlink at the source will navigate to the target. Hyperlinks can assume any of the following appearances:

Questions 4:- How to link a document?

Answer:- The HTML <a> tag defines a hyperlink. Anchor tag is use to link a document with text.It has the following

syntax: <a href=”url”>link text</a>

The most important attribute of the <a> element is the href attribute, which indicates the link’s destination.

Questions 5:- what is the use of name attributes?

Answer:- The name attribute specifies the name of an <input> element.

The name attribute is used to reference elements in a JavaScript, or to

Questions 6:- Define anchor tahg with href attribute.

Answer:- The <a> tag defines a hyperlink, which is used to link from one page to another.

The most important attribute of the <a> element is the href attribute, which indicates the link’s destination.

Example:- <a href=”www.google.com” > GOOGLE!</a>

Triangle property

Triangle

Triangle is a 2D shape. it is made of 3 side (edge). The sum of interior angle is 180. The sum of exterior angle is 360.

Triangle can classified in three type on the basis angle.

1. Right angle triangle :- A triangle which one angle is right angle is known as Right angle Triangle.

Area of right angle triangle :- The area of a right angle triangle can be calculated by the Following method.

1 Heron's formula :If the measurements of three sides are given then we can calculate the area of right angle triangle by using Heron's formula.

Let the measurements of three sides are a, b and c. Then the area of right angle triangle will equal to.....

Semi perimeter = sum of all sides / 2

 

2. Height are Given:- if the perpendicular height and base of triangle are given then we can calculate the area of right angle triangle by using following formula.

Area = 1/2 Base x perpendicular height 

P

Triangle Test Page

Class VIII math viva exercise 6.4

 

home work

सभी क्षात्र निर्देशो को सही से पढो और जवाब दो 

How to Balance achemical Reaction

 

Balancing a chemical reaction involves adjusting the coefficients of the reactants and products in the chemical equation so that the same number of atoms of each element is present on both sides of the equation. Here's a step-by-step guide on how to balance a chemical reaction:

1. Write the unbalanced chemical equation: Start by writing down the chemical equation for the reaction, including all the reactants and products. Ensure that the chemical formulas for the compounds are correctly written.

2. Count the number of atoms of each element: Count the number of atoms of each element on both the reactant and product sides of the equation. Make a list of the elements and the corresponding number of atoms.

3. Balance the atoms one at a time: Begin balancing the equation by adjusting the coefficients of the compounds to ensure that the same number of atoms of each element is present on both sides of the equation. Start with the elements that appear only once on each side of the equation.

4. Use coefficients to balance: Adjust the coefficients of the compounds in the equation to balance the number of atoms of each element. You can change the coefficients but not the subscripts of the chemical formulas.

5. Balance polyatomic ions as single units: If a polyatomic ion appears on both sides of the equation, treat it as a single unit and balance it as such.

6. Check your work: Once you have balanced the equation, double-check to ensure that the number of atoms of each element is the same on both sides of the equation. Also, verify that the coefficients are in the simplest whole-number ratio.

7. Adjust coefficients if necessary: If the coefficients are not in the simplest whole-number ratio, multiply all coefficients by the same factor to achieve this. This step ensures that the equation is correctly balanced.

8. Finalize the balanced equation: Write down the final balanced equation with the correct coefficients for all compounds.

It's important to note that balancing chemical equations requires practice and patience. Some reactions may be more complex than others, requiring multiple steps to achieve balance. Additionally, it's essential to follow the rules of chemical nomenclature and valency while balancing equations to ensure accuracy.

Corrosion and prevntion method

 

Corrosion is the degradation of materials, particularly metals, due to chemical reactions with their environment. It can lead to structural weakening, aesthetic deterioration, and functional failure of the affected materials. Preventing corrosion is essential to maintain the integrity and longevity of metal structures, equipment, and components. Here's how corrosion can be prevented:

1. Protective Coatings: Applying protective coatings, such as paints, varnishes, epoxy coatings, or specialized corrosion-resistant coatings, can create a barrier between the metal surface and the corrosive environment. These coatings act as a physical barrier, preventing moisture, oxygen, and other corrosive substances from coming into contact with the metal surface.

2. Galvanization: Galvanization involves coating steel or iron with a layer of zinc to protect it from corrosion. The zinc coating acts as a sacrificial anode, meaning it corrodes preferentially to the underlying metal, thus providing cathodic protection to the base metal. Galvanized coatings are commonly used in outdoor applications, such as fencing, roofing, and structural components.

3. Cathodic Protection: Cathodic protection is a technique used to protect metal structures from corrosion by making them the cathode in a galvanic cell. This can be achieved through impressed current cathodic protection, where an external power source is used to supply electrons to the metal surface, or sacrificial anode cathodic protection, where a more reactive metal is connected to the metal structure to serve as a sacrificial anode.

4. Proper Material Selection: Choosing corrosion-resistant materials for specific applications can help prevent corrosion. Stainless steel, aluminum, copper, and certain alloys are known for their resistance to corrosion in various environments. When selecting materials, factors such as exposure to moisture, temperature, pH, and chemical exposure should be considered.

5. Controlled Environment: Controlling the environment in which metal structures are located can help prevent corrosion. This may involve controlling humidity levels, temperature, and exposure to corrosive substances such as saltwater, acids, or pollutants. Proper ventilation and drainage systems can also help minimize moisture buildup, which is a common cause of corrosion.

6. Regular Maintenance: Regular inspection and maintenance of metal structures are essential for identifying and addressing corrosion issues before they escalate. This may include cleaning the surface, repairing damaged coatings, and applying corrosion inhibitors or protective coatings as needed. Prompt repair of scratches, dents, or other damage to the protective coating can help prevent corrosion from spreading.

7. Corrosion Inhibitors: Corrosion inhibitors are chemicals that can be added to coatings, paints, or applied directly to metal surfaces to inhibit the corrosion process. These inhibitors work by forming a protective film on the metal surface, blocking the interaction between the metal and corrosive agents. Common corrosion inhibitors include chromates, phosphates, and organic compounds.

By implementing these corrosion prevention methods, industries can minimize the impact of corrosion on metal structures and equipment, reduce maintenance costs, and extend the service life of assets.

Rancidty

 

Rancidity is a term used to describe the unpleasant odor and taste that develops in fats and oils when they undergo oxidation. It is a common problem in foods containing fats and oils, leading to a deterioration in their quality and palatability.

There are two main types of rancidity:

1. Hydrolytic Rancidity: This type of rancidity occurs when fats and oils react with water in the presence of enzymes called lipases. Hydrolytic rancidity typically occurs in foods with high moisture content, such as meats and dairy products. The lipases break down the fats into free fatty acids, which can have a sour or off-flavor.

2. Oxidative Rancidity: Oxidative rancidity occurs when fats and oils react with oxygen in the air, leading to the formation of volatile compounds that produce off-flavors and odors. This type of rancidity is more common and can occur in a wide range of foods, including nuts, seeds, cooking oils, and processed foods containing fats and oils. Factors such as exposure to light, heat, and air can accelerate oxidative rancidity.

Both types of rancidity can be detrimental to the quality, flavor, and nutritional value of foods. Rancid foods are often described as having a stale, cardboard-like taste and a rancid or unpleasant odor. In addition to affecting the sensory characteristics of foods, rancidity can also lead to the degradation of essential fatty acids and the formation of potentially harmful compounds.

To prevent rancidity, it is important to store fats and oils properly in airtight containers, away from heat, light, and moisture. Additionally, antioxidants such as vitamin E (tocopherol) and butylated hydroxytoluene (BHT) can be added to foods to help inhibit oxidation and prolong their shelf life. Proper food handling and storage practices can help minimize the risk of rancidity and ensure the quality and safety of food products.