Describe the early computing machines and their inventors in the dark age.

DEVICES USED IN DARK AGE 

1. Abacus 

About 5,000 years ago 'abacus' was invented in China. It is considered as the first computer. It is a rectangular frame with vertical wires containing a number of beads for representing units, tens, hundreds, thousands and so on. Calculations were done by moving the beads along with the wires. The structure of abacus is divided into two parts, the upper part is called the 'HEAVEN' and lower part the 'EARTH'. 

2. Napier's Rods 

In 1612, John Napier made the first printed use of the decimal point and invented logarithms and he designed a device called Napier's rods or bones. This device consisted of a set of eleven rods or bones with number marked on them. By placing these rods side by side products and quotients of large numbers could be obtained very easily. 

3. Oughtred's Slide rule 

In 1622, Oughtred developed a slide rule based on Napier's logarithms that was uses! by engineers as primary calculator. It was consisted of two movable rulers placed side by side. Each ruler is marked in such a way that the actual distances from the beginning of the ruler are proportional to the logarithm of the numbers printed on the ruler. By sliding the rulers multiplication and division could be done quickly. 

4. Pascaline (Pascal's Calculator) 

In 1640a French mathematician, Blaise Pascal started developing a device to add sums of money. In 1642 he invented the first operating model a numerical wheel calculator. This brass rectangular box,also called a Pascaline, used 8 movable dials to add numbers upto eight figures long. Pascal's device used a base of ten to accomplish this. It could perform addition and subtraction only, while multiplication and divisions were implemented by performing a series of addition and subtractions. In fact this device could really only add, because subtractions were performed using complement techniques. Modern computers use similar complement techniques for subtraction. 

5. G.W. Leibniz's 

Calculator Leibniz improved on Pascal's calculator in 1694 by creating a machine, that could also multiply. Leibniz's mechanical multiplier worked by a system of gears and dials. 

6. Jacquard's Loom 

In ( 820 French Weaver Joseph Marie Jacquard invented the first punch card to control the patterns to be woven. Jacquard's Loom is considered the first significant use of binary automation. 

7. Arithometer 

Charles Xavier Thomas de Colmar, a Frenchman invented a machine in 1820 that could perform the four basic arithmetic operations. Colmar's mechanical calculator, the Arithometer, presented a more practical approach to computing 

HISTORY AND DEVELOPMENT OF COMPUTER

Into how many ages is the computer era divided 

AGES OF THE COMPUTER ERA 

The computer era is divided into three ages: 
1. The Dark Age (5000 B.C. to 1890 A.D.) 
2. The Middle Age ( 1890 A.D. to 1944 A.D.) 

What are the limitations of the computers

LIMITATIONS OF THE COMPUTERS 

1. No ability to generate Information 

A computer cannot generate information on its own. 

2. No ability to correct 

A computer cannot correct wrong instructions. 

3. No decision at its own 

A computer cannot come up with an original decision. 

What are the Capabilities of computer

CAPABILITIES OF COMPUTER 

1. Speed 

A Computer can process data faster than any other machine designed to perform a similar task. 

2. Repetitions 

A computer can tirelessly perform the same operations millions of times in exactly the same way without getting bored and tired as a human clerk would. 

3. Accuracy 

A computer's high-speed processing is accompanied by high-accuracy results. No other system can have as much accuracy as a computer system. 

4. Logical operations

The computer can make decision based on some conditions and take alternative course of action accordingly. 

5. Store and recall information 

The computer is like human brain as it can store facts, instructions and information and recall them when needed. 

6. Self-checking 

The computer verifies the accuracy of its own work by means of a parity check. 

7. Self-operating 

Once the data and program are fed into the computer memory, the computer is capable of executing the instructions on its own, without human intervention. 

Describe some of the characteristics of computers.

CHARACTERISTICS OF COMPUTER 

1. Machine:

It is a machine. It is an inanimate object. It needs outside intervention for it to run. It can only do things for which it is designed. 

2. Electronic:

It is Electronic because it is made up of electronic circuits. It runs on electrical energy. 

3. Automatic:

It is automatic. Once started it continues to run without outside intervention. 

4. Data Manipulator:

It can manipulate data, following specific rules. It can perform arithmetic functions such as addition, subtraction, multiplication, and division. It can compare data.

 5. Memory: 

It has memory. It has the capacity to remember what it has done. It can store instructions in its memory and follow these through unaided. 

Write a note on Software.

SOFTWARE DEFINITION

Software refers to the programs that instruct the computer what to do. Software makes the computer useful. Software is the set of all the programs (instructions) and data necessary to make the computer usable.

Examples Windows

Visual Basic, Norton antivirus, Microsoft Word, Microsoft Excel etc.

TYPES OF SOFTWARE

Software are of two types. 
• System Software 
• Application Software 

Write a note on Hardware.

HARDWARE DEFINITION

The physical or tangible components forming a computer are called Hardware. When people talk about a computer, they usually mean the hardware.

Or 

The physical components of computer and other attached input ad output devices are called hardware. 

COMPONENTS OF HARDWARE 

Hardware is a collective term. All hardware components may be connected mechanically electrically or electronically with each other. It includes the cables, connecters, power supply units and peripheral devices such as.

• Keyboard 
• Mouse 
• Audio speakers 
• Printers 

Define Computer

DEFINITIONS OF COMPUTER

Computer is an electronic device that accepts data and instructions (in form of programs) as input, processes that data according to the given instructions and produces information as output.

OR

Computer is a machine that can accept input data, processes it and gives output.

OR

A computer is an electronic device that can interpret and execute programmed commands for input, output, computation and logic operations.

OR

A computer is an automatic electronic calculating device which can process given data and gives results.

OR

A computer is a device capable of accepting data and gives desired result by processing.

OR

A computer is a device which processes the given data with the help of a stored program at high speed. 

My Aim In Life

Everyone in the world, however great or small, has some aim in Life. A prince may have an aim to be a king and a king may have an aim to be an emperor. A professor aims at being a principal and a peon aims at being a head-peon. Someone's aim for fame, someone's aim for power, someone's for money; while some aim at acquiring knowledge.

I have also a high aim of life though I do not know how far I would be able to realise it. I do not want to run after money, nor after cheap popularity. I have resolved to be a doctor and spend my life in the service of others. I believes it is a good selection. I would not charge high fees and shall never exploit the needy and the poor at the most critical moments of their life.

If were a good a doctor, I would, of course, get fame and popularity. Being a good doctor; having connections with several families, I would naturally acquire power and influence. This profession gives better greater opportunities to serve mankind in their moments of urgent need, when they are involved in a struggle of life and death.

My aim does not end there I shall devote a part of my time in doing free work in charitable dispensaries. I shall follow the principles of truth and justice. Whether I achieve anything substantial in my life is another matter, but I shall always strive to keep my aim pure, honest and honourable. 

Patriotism Essay

Patriotism means love for one's country. This love is not created by any artificial methods, but it is already deeply rooted in our heart. Patriotism is an instinct which comes to us from the moment we are born. There are some, who think that patriotism is a narrow-minded sentiment, and a sign of a semi civilized state of mind.

A man loves the whole universe and considers all people of the world as his brethren. This idea of universal brotherhood makes every man a citizen of the world and not of his narrow world, known as his country. We should not be narrow-minded patriots. Love of one's country should not and does not mean hatred of the rest of the world. It is a false patriotism which makes us hate other countries.

True patriotism is based on unselfish love for our country and our respect for its history and culture. It makes us great and teaches us to love mankind as one family, created by one God and governed by the laws of one universe.

A true patriot, therefore, will never like to say such things about other countries as he would not tolerate about his own country. True patriotism demands sacrifices of ones life, family, property and everything. Those who lay down their lives for the sake of the mother-country are martyrs. 

STATES OF EQUILIBRIUM

STATES OF EQUILIBRIUM 

There are three states of equilibrium. 
They are the following. 

STABLE EQUILIBRIUM 

Definition 
A body is said to be in stable equilibrium if it returns to its original position when tilted a little. 
                                                                                               OR 
The centre of gravity of a body rises with a jerk is called stable equilibrium. 
Examples 
• Book on a table. 
• Chair on flat ground. 
• Table on a floor. 
• A standing car on a smooth road. 

UNSTABLE EQUILIBRIUM 

Definition
 A body is said to be in unstable equilibrium if it moves further away from its original position when tilted a little. 
                                                                                               OR 
The C.G of a body lowered with a slight move the equilibrium of that body is called unstable equilibrium. 
Examples 
• A stick standing vertically on the tip of a figure. 
• A standing pencil on the table. 
• An acrobat walking on a rope. 

NEUTRAL EQUILIBRIUM 

Definition 

A body is said to be in neutral equilibrium if it neither returns to its former position nor moves further away when tilted a little. 

                                                                                                OR 

The equilibrium of that body is called neutral equilibrium whose C.G is neither raised nor lowered on disturbing.

Examples 

• Horizontally lying cylinder and funnel. 

• Lying a ball on the floor. 

CENTRE OF GRAVITY  

Definition 

It is the point at which the entire weight of the body is said to be situated. 

                                                                                                 OR 

The point on a body at which the whole weight of the body appears to act. It may be on the body or out side the body in case of a hollow object. 

TORQUE OR MOMENT OF A FORCE

Definition 

It is the turning effect of a force about the axis of rotation. 
Formula 
Torque = force x moment arm 
                t =f x d 
Unit 
Its unit is N-m. 

TYPES OF TORQUE 

Torque or moment may rotate a body in clock wise or anti clock wise direction. 

NEGATIVE TORQUE 

The clock wise torque is called negative torque. 

POSITIVE TORQUE 

The anti clock wise torque is called positive torque. 
Notation It is denoted by the Greek letter t (tau) 
Formula 
Torque = Force x moment arm. 
                        t= F x d 
Unit The unit of torque is (N-m) 
Nature 
It is a vector quantity. 

MOMENT ARM 

Definition 
The perpendicular distance between the line of the force and the axis of rotation is called the moment arm. 
Notation 
It is denoted by d. 

FACTORS ON WHICH TORQUE DEPENDS

 Torque depends upon two factors. 
1. Magnitude of the applied force. 
2. The moment arm Torque increases with the increase of force. Torque is directly proportional to the applied force. Torque is directly proportional to the moment arm. 

PRINCIPLE OF MOMENT

Statement 

According to the principle of Moment -If a system is in equilibrium under influence of some Torques then the sum of clock wise torques is equal to the sum of anti clock wise torques i.e. 

Mathematically 

In Equilibrium position. 

Clock wise torque = Anti clock wise torque. 

EQUILIBRIUM

Definition 

When the resultant of all the forces acting on a body comes to zero, the body is said to be in the state of equilibrium. 
                                                                                             OR 
In other words the body is said to be in the state of equilibrium if left-ward forces are equal to the rightward forces and upward forces are equal to the downward forces. 
Example 
• A book lying on the table.
 • A train moving in a straight line with a constant velocity. 
• A body hanging at rest from the ceiling by a vertical string. 
• A Paratrooper moving down with uniform velocity after opening his parachute. 

TYPES OF EQUILIBRIUM  

There are two types of equilibrium. 
1. Static equilibrium 
2. Dynamic equilibrium 

STATIC EQUILIBRIUM 

Definition
If some forces are acting on a body vertically or horizontally and the body maintains its state of rest, Then it is called static equilibrium. 
Example 
• A book lying on the table. 
• A body hanging at rest from the ceiling by a vertical string. 

DYNAMIC EQUILIBRIUM 

Definition 
If some forces are acting on a body vertically or horizontally and the body maintains its state of motion, then it is called dynamic equilibrium. 
Example 
• Train moving with uniform velocity.
• Paratrooper falling down with uniform velocity. 

CONDITIONS OF EQUILIBRIUM  

FIRST CONDITION OF EQUILIBRIUM 

 Statement 
The body is said to be in the state of equilibrium if the resultant of all forces acting on a body is equal to zero i.e.

In other words the algebraic sum of all the forces acting along X-axis should be zero i.e.

And the algebraic sum of all the forces acting along Y-axis should be zero i.e. 

When first condition of equilibrium is satisfied. the body is in translational equilibrium and there is no linear acceleration. 

SECOND CONDITION  OF EQUILIBRIUM 

Statement The body is said to be in the state of equilibrium if the sum of all the torques or moments acting on the body must be zero i.e. 

RESULTANT OF TWO FORCES

Definition 

The net effect of the forces is a single force which is called the resultant of the forces. 
                                                                    OR 
A single that gives combined effect of forces is called resultant force. 

 

If two forces F1 and F2 are acting on a body at a straight line but in opposite direction and body remains at rest or in equilibrium. Then we say that F1 and F2 are equal in magnitude but opposite in direction. 

If two forces F1 and F2 are acting on a body at a straight line but in opposite direction and body moves in the direction of any one of them which is greater than the other. Net force is calculated as: 

                               F2-F1 net force
                   or        F1-F2 net force
            Body will move in the direction of greater force.

RESULTANT OF TWO FORCES ACTING AT AN ANGLE

 If two forces are acting on an object making a certain angle. In this case the force can be represented in magnitude and direction by two adjacent sides of a parallelogram (I In). The resultant force FR is a vector represented by the diagonal from the point of intersection. This is called the parallelogram of forces.

As PR is diagonal of I Im PQRs so the resultant is diagonal. And the I Im is called I Im of force F1 and F2. 


By head to tail rule, we can draw force F- from the terminal point of force F2. To get the resultant FR we draw a vector from the initial point of force F2 to the terminal point of the force Fr. This is the same force as obtained from the I l 1 of force as shown in the figure.