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Showing posts with the label Physics

### Importance of Physical Exercise according ot age and sex

Importance of Physical Exercise according ot age and sex According to Age: Physical education is applicable for people of all ages. But programmes of physical education differ likings and dislikings for different age-groups. Not only physical exercise but also food, likings and dislikings and physical abilities are different for different age-groups. For example, physical ability of children is not equal to that of adults.  So to develop the abilies exercise through games should be introduced accordingly. Frog jumps, touch and back, crow jump or recreational games are some physical activities that can improve physical ability of children. Selection of exercise and games for adolescent should be done systematically. Standing in a line, exercise of hands and legs, running with a ball, touch and play, etc. and games and physcial exercise can be used to develop physical abilities of children. Remember, children and adolescents should not participate in weight lifting exercise. It causes h

Centigrade and Fahrenheit Scales The earliest thermometer was constructed by Galileo in 1593. Newton suggested the necessity of the fixed points. The temperature of the melting point of ice is taken as the lower fixed point and the temperature of steam at a pressure of 76 cm of Hg (normal pressure) is taken as the upper fixed point. Centigrade (or Celsius) Scale Celsius, in 1742, suggested the centigrade system of temperature. He marked zero at the lower fixed point and 100 at the upper fixed point. The interval between the two fixed points is divided into 100 equal parts. Each part or degree represents 1°C or 1° Celsius. The scale is also known as the Celsius scale. Fahrenheit Scale Fahrenheit, in 1720, suggested this scale by taking zero as the temperature of the human body. Later the correct temperature of the human body on this scale was found to be 98.4°F. The lower fixed point is marked as 32 and the upper fixed point is marked as 212. The interval is divided into 180 equal p

### Relation Between Celsius, Kelvin, Fahrenheit and Rankine Scales of Temperature

Relation Between Celsius, Kelvin, Fahrenheit, and Rankine Scales of Temperature In the figure, the temperatures of absolute zero, the melting point of ice, and the boiling point of water as measured on the Celsius (Centigrade), Kelvin (absolute), Fahrenheit, and Rankine scales are shown. Celsius and Fahrenheit's scales show the same reading at - 40° i.e., - 40° = - 40°F. The Kelvin scale and the Rankine scale agree at zero degrees only. The temperatures represented have been rounded off to the nearest degree. You may also like What is considered a fever? What is physical education? What is PanSexual? What is price discrimination? What is sham bedding?

### Liquid Thermometer

Liquid Thermometer Liquid thermometers are based on the principle of change of volume of the liquid with change in temperature. These thermometers are suitable for a narrow range of measurements. The most commonly used liquids are (i) mercury and (ii) alcohol. The range of the mercury thermometer is - 39°C to 357°C. Alcohol thermometers are used only to measure temperature near ice points. Mercury Thermometer Mercury is usually selected for use in liquid in glass thermometers for the following reasons: It has a low specific heat and hence it absorbs little heat from the body whose temperature is being measured. It is a good conductor of heat and takes the temperature of the body quickly. It can be easily seen in a fine capillary tube and the thermometer can be made sensitive. It does not wet the wall of the glass tube. This is an important point for the construction of a thermometer. It has a uniform coefficient of expansion over a wide range of temperatures. It remains a liquid ov

### Types of thermometer

Types of thermometer There are different kinds of thermometers. 1. Liquid Thermometers These thermometers are based on the principle of change in volume of a liquid with change in temperature. Mercury and alcohol thermometers are based on this principle. 2. Gas Thermometer These are based on the principle of change in pressure or volume with change in temperature, e.g., Callendar's constant pressure thermometer, constant volume hydrogen thermometer, etc. 3. Resistance Thermometers These are based on the principle of change in resistance with a change in temperature, e.g., platinum resistance thermometer. 4. Thermoelectric Thermometers These are based on the principle of thermoelectricity, i.e., the production of thermo-E.M.F. in a thermo-couple when the two junctions are at different temperatures. The various thermometers commonly used are: Copper and constantan Iror and constantan Chromel and constantan Chromel and alumel Platinum and Rhodium 5. Radiation Thermometers These

### What is thermometry?

Thermometry The branch of heat relating to the measurement of the temperature of a body is called thermometry. The thermometer is an instrument used to measure the temperature of a body. The essential requisites of a thermometer are given as under:  1) Construction, 2) Calibration, and 3) Sensitiveness. For the construction of a thermometer, the proper choice of a substance, whose physical property varies uniformly with rising in temperature, is essential. 1) Construction The physical property of a substance plays an important role in the construction of a thermometer. In a mercury thermometer, the principle of expansion of mercury with rising temperature is used. The platinum resistance thermometer is based on the principle of the change in resistance with a change in temperature. The gas thermometer is based on the principle of change in volume or pressure with a change in temperature. 2) Calibration  When a thermometer is constructed, it should be properly calibrated. The standa

### Heat and Temperature

Heat and Temperature What is heat? What is temperature? Heat is a kind of energy. We have seen that energy can do work. By applying force it is possible to displace a body in the direction of the force, for example, heat is produced by burning fuel oil in a train or a car and this produced energy creates motion in the train or car. So this new form of energy is called heat energy like electricity or kinetic energy. It is interesting that if we could see on the molecular level i.e, looking at any substance if we see its molecules, we should call it "kinetic energy" instead of the "heat energy". We may regard heat as the physical cause of the sensation of hotness, coldness, and temperature as the degree of hotness or coldness. We know that a liquid flows only from higher to a lower level until a common level is attained, irrespective we the quantity of liquid at two levels. We replace the quantity of heat liquid with the quantity of heat and its level of temperature

### Human Bodies and Machines

Human Bodies and Machines In our daily life, we use many different types of devices. To travel we use cars, to preserve the food we keep them in the refrigerator, for comfort on hot days we turn on the electric fan, to learn news we watch the television, etc. This list is very long and for that reason, we can understand what a machine or device means. We know that the human body cannot be called a machine. A complete human being is created from just a single cell. There is no machine in this world that starts from a small unit and then transforms into a complete machine on its own. If any malfunction arises within the body, an automatic repair mechanism gets initiated, but no machine can do such a thing. But, still, to compare with the known world or to describe the functions of the different organs of the body, we often compare the human body with machines. For example, it can be said that our heart is an automatic pump that circulates blood spontaneously without any external stim

### Contributions of Jagadish Chandra Bose

Contributions of Jagadish Chandra Bose Acharya Sir Jagadish Chandra Bose was a renowned physicist, as well as a successful biologist. He was the first internationally recognized scientist of this subcontinent. The forefathers of Jagadishchandra Bose lived at the village of Rarikhal of Bikrampur in Dhaka district. He was born in 1858 in Mymensingh. His father, Bhagaban Chandra Bose, was a deputy magistrate of the Faridpur district. Acharya Sir Jagadish Chandra Bose His education started in a rural school in Faridpur. Later he completed his studies at Hare School and Saint Xavier School and College in Kolkata. After passing his B.A. in 1880, he went to England, and from 1880 - 1884 he completed his honors with BA in Physics from Cambridge University and then acquired a B.Sc. degree from London University. Returning to his motherland in 1885, he became a professor of physics in Presidency College. At that time was not enough scopes for research in that colleges, but he continued his res

### Background of Biophysics

Background of Biophysics Biology tries to understand the diversity of the living world and the process through which living things lead their lives. How do the animals collect food, develop relations with one another, perceive the environment and reproduce all these are the subject matter of biology. On the other hand, the laws followed by the physical world of nature and the simple mathematical explanations of those laws are the subject matter of physics. It may seem that there is no link between the simplicity of physics and the complexity of biology. But with the advancement of science, and depending on its different branches, a relation has been established between biology and physics. This new field has been named biophysics. Biophysics employs the simple and mathematical laws of physics in the complex processes of biology and thus investigates various mysteries of life. Biophysics is the bridge between biology and physics. Biophysics in one way can identify the arrangement of

### Efficiency

Efficiency Efficiency: The ratio of the amount of work we get from an engine given is its efficiency. Effective Energy: The energy that we get from an engine is its effective energy. What do you mean by 70% efficiency of a pump? 70% efficiency of an engine means 100 J input of energy in the engine yields 70 J efficient energy and the rest of 30 J energy is wasted. Secondary Physics Chapter - 1 :  Physical Quantities and Their Measurements Chapter - 2 :  Motion Chapter - 3 :  Force Chapter - 4 :  Work, Power, and Energy Chapter - 5 :  State of Matter and Pressure Chapter - 6 :  Effect of Heat on Matter Chapter - 7 :  Waves and Sound Chapter - 8 :  Reflection of Light Chapter - 9 :  Refraction of Light Chapter - 10 :  Static Electricity Chapter - 11 :  Current Electricity Chapter - 12 :  Magnetic Effects of Current Chapter - 13 :  Modern Physics and Electronics Chapter - 14 :  Physics to Save Life

### Role of Energy in Development Activities

Role of Energy in Development Activities There is a very close relationship between the development of a country and the use of energy. To speak the truth, energy use may be considered the first parameter to see how developing a country is. We should pay our first attention to education for the development of our country. A lot of students in our country are studying in schools, colleges, and universities. We have to ensure an adequate supply of electricity to run these institutions properly. They need light for studying at night and their studies are hampered if the electricity supply is not ensured. Laboratories are to be used, and computers and networks are kept active for higher education, which has no alternative other than the supply of electricity. Agriculture plays an important role in the economy of our country. As the country is small, the amount of suitable agricultural land is less, and it is further decreasing. Our country has achieved self-sufficiency in food by growing

### Work

Work What is work? If because force-displacement happens then the product of force and component of displacement at the direction of force due to force is work. Work is the product of applied force on a body and its displacement along the direction of a force. Unit of work: J (Joule) Dimension of work, [W] = ML 2 T -2 What is Joule? If due to the appliance of one-newton force at the direction of force the application point of force moves 1 meter then it is 1 joule of work. What is positive work? If due to force the application point of force moves along the direction of force or the component of displacement is towards the direction of force then it is said to be work done by force or positive work. What is negative work? If due to force the application point of force moves in the opposite direction of force or the component of displacement is at the opposite direction of force then it is said to be work done on force or negative work.  What do you mean by the work 50 J? The work

### Development of Physics

Development of Physics Modern civilization is the product of science. Behind this development of science, there are untiring efforts, discoveries, and innovations of scientists. Science has no national or political boundaries. The growth, development, and benefit of science are enjoyed by all people of all nations. From ancient time scientist have been contributing to the development of science. In this lesson, we will try to mention the contributions of physicists. Thales (624-569 B.C) is famous for his predictions regarding solar eclipse. He also knew about the magnetic properties of loadstone. Pythagoras (527-497 B.C) is a memorable name in the history of science. Besides the invention of several Geometric theorems, he made a longer-lasting contribution through his works on vibrating string. He was given several Geometric theorems. Moreover, he made long-lasting contributions through his works on vibrating strings. The present scales of musical instruments and music are partially th

### Scope of Physics

Scope of Physics Since physics is the oldest and the most fundamental branch and other branches somehow flourished on the basis of physics, it is very natural that the scope of physics is very vast. Not only that, different technologies have flourished based on different laws of physics and we are using these in our daily lives (there are examples of some instruments used in medical science in the final chapter).  At present the greatest contribution behind civilization is of electronics and physics has the greatest contribution behind civilization is of electronics and physics has the greatest contribution to this technology also. Besides daily activities, from destruction of war to space exploration, the contribution of physics is present. Not only that, by the combination of other branches of science and physics, newer branches have developed, for example, astrophysics consists of astronomy and physics. In order to explain organic processes, biophysics has been built up by the

### Objectives of Physics

Objectives of Physics Physics unearths the mystery of nature:  Physics is the fundamental branch of science because its principles are the basis of other branches of science. For example, the principle of conservation of energy is a principle of physics used to explain the wide range of science starting from the structure of atoms to weather forecasting. Although the main function of physics is to study matter and energy, the main objective of physics is to realize the rules of nature as well as unearthing the mystery of nature. At the beginning of the twentieth century, physicists discovered that electrons revolve around the positively charged nucleus of an atom. Subsequent experiments proved that the nucleus consists of protons and neutrons. Now the physicists have discovered that protons and neutrons are formed of smaller particles. The study of physics helps not only to understand and explain natural events but also its application plays a vital role in other branches of science.

### What is a generator? What is the function of a generator?

What is a generator? What is the function of a generator? A generator is a power generating device with which kinetic energy is converted to electrical energy. The making of a generator is based on the principle of electromagnetic induction. Most of the electricity we use in our homes is produced by generators. Inside a generator, coils of wire are rotated between the poles of a magnet. As the coils rotate, they cut through magnetic field lines generating current. You May Like What is a generator?  What is the function of a generator? What do you mean by alloy? Explain the importance of recycling metal? What is galvanizing?

### Physics to Save Life

Physics Chapter - 14: Physics to Save Life ðŸ‘‰   All Chapter Contents   ðŸ‘ˆ   14.1 Background of Biophysics 14.2 Contributions of Jagadish Chandra Bose 14.3 Human Bodies and Machines 14.4 Diagnostic Instruments 14.5 Physics in Treatment Question Bank 14.1  Background of Biophysics 14.2 Contributions of Jagadish Chandra Bose 14.3 Human Bodies and Machines 14.4 Diagnostic Instruments 14.5 Physics in Treatment Secondary Physics Chapter - 1 :  Physical Quantities and Their Measurements Chapter - 2 :  Motion Chapter - 3 :  Force Chapter - 4 :  Work, Power, and Energy Chapter - 5 :  State of Matter and Pressure Chapter - 6 :  Effect of Heat on Matter Chapter - 7 :  Waves and Sound Chapter - 8 :  Reflection of Light Chapter - 9 :  Refraction of Light Chapter - 10 :  Static Electricity Chapter - 11 :  Current Electricity Chapter - 12 :  Magnetic Effects of Current Chapter - 13 :  Modern Physics and Electronics Chapter - 14 :  Physics to Save Life

### Modern Physics and Electronics

Physics Chapter - 13: Modern Physics and Electronics ðŸ‘‰   All Chapter Contents   ðŸ‘ˆ   13.1 Radioactivity 13.2 Development of Electronics 13.3 Analog and Digital Electronics 13.4 Semiconductor 13.5 Information and Communications Technology 13.6 Internet and E-mail 13.7 Effective Use of ICT Question Bank 13.1  Radioactivity 13.2 Development of Electronics 13.3 Analog and Digital Electronics 13.4 Semiconductor 13.5 Information and Communications Technology 13.6 Internet and E-mail 13.7 Effective Use of ICT Secondary Physics Chapter - 1 :  Physical Quantities and Their Measurements Chapter - 2 :  Motion Chapter - 3 :  Force Chapter - 4 :  Work, Power, and Energy Chapter - 5 :  State of Matter and Pressure Chapter - 6 :  Effect of Heat on Matter Chapter - 7 :  Waves and Sound Chapter - 8 :  Reflection of Light Chapter - 9 :  Refraction of Light Chapter - 10 :  Static Electricity Chapter - 11 :  Current Electricity Chapter - 12 :  Magnetic Effects of Current Chapter - 13 :  Modern Physics an