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John Donne • Name: John Donne • Birth: 22 January 1572, London, England • husband : . • Mother: Elizabeth Howwood. • wife husband : . Early life of John Donne:         John Doe was an English poet and cleric in the Church of England They are considered pre-eminent representatives of metaphysical poets. His compositions are known for his strong, sensual style and include sonnet, love poems, religious poems, Latin translations, epigrams, elegans, songs, satire and sermons. His poetry is famous for his inventiveness of language and his inventiveness of metaphor, especially in comparison to his contemporaries. Don's style is characterized by sudden opening and various contradictions, irons, and dislikes.         With their constant dramatic or everyday speech rhythm, their stressful syntax and their lucrative eloquence, these attributes were a reaction against the lubrication of traditional Elizabethan poetry and the adaptation of Eur...

Henrik Ibsen Henrik Ibsen • Name: Heinrich Johan Ibssen • Born: March 20, 1828, Skåne, Telemark, Norway. • Father: Nood Ibnsen. • Mate: Marichien Alenburg • Wife / Husband: Suzanne Thomson Early life of Henrik Ibsen:         Heinrich Johann Ibsen was the Norwegian playwriter, theater director and poet. As one of the founders of modernity in the theater, Ibsen is often called "Father of Realism" and is one of the most influential dramatists of his time. His main works include Brand, Peer Giant, An Enemy of the People, Emperor and Galilean, A Doll House, Heather Gabbler, Ghosts, The Wild Duck, When We Dead, Awakeen, Pillars of Society, The Lady from the Sea, Rosemarshom, Are. Master Builder, and John Gabriel Borkman He is the most dramatist in the world after Shakespeare, and in the early 20th century, A Doll House became the world's most performed play.         Many of his later plays were considered malignant for many of his era...

What is Physics? Physics  is that branch of science which deals with the study of the phenomena of nature. The word " physics ' itself is derived from a Greek word meaning nature. Know major branches of physics What do you understand by the word 'science'? A systematic knowledge collected through experimental observation of the natural events is known as science. What do you mean by physical word? Universe or physical world implies the collection of living or non living objects around us. Scope and excitement of  physics A)   Physics  deals with a wide variety of fields such as mechanics, sound, electricity, magnetism, optics, modern  physics  etc. Through there is great diversity in the fields but there is much similarity I the concepts, principles and methods of analysis used in these fields. Read Also:  Example of current electricity B) The field of mechanics deals with the study of the properties and laws of solids, ...

What is acceleration of a body? Acceleration of a body is defined as- 1) The acceleration of a particle or a body is defined as the time rate of change of velocity of it i.e. Acceleration = change in velocity/time taken. 2) The acceleration of a body is change in the velocity in a unit time. 3)  Acceleration of a body  is vector quantity. 4) The acceleration of a particle or body can be positive, negative or zero. 5) A cceleration of a body  is positive if the velocity of the body is increasing with time and is negative if the velocity of body is decreasing with time. 6) The negative acceleration is also called retardation or deceleration. 7) CGS unit of acceleration is cm/s2. 8) The dimensional formula for acceleration is [ M 0 L 1 T -2 ]. 9) If  acceleration of a body  is zero, then the body is moving with constant velocity. Uniform acceleration a) An object is said to be moving with a uniform acceleration if its...

What is adiabatic process? Adiabatic process : 1. An adiabatic process is one in which pressure, volume and temperature of the system change but there is no exchange of heat between the system and the surroundings. 2. An adiabatic process may be achieve a) If the gas is enclosed in a vessel whose walls are made of a highly insulating material and b) The gas is compressed or allowed to expend very quickly. 3. When the gas expands, cooling will take place. Because the process takes place very quickly and the walls are made of insulating material, hence no heat cans either the system from surroundings. On the other hand, when the gas is compressed quickly, heat cannot escape to surroundings through the insulating walls and temperature of gas gets increased. 4. In case of an adiabatic process taking place in an ideal gas , internal energy of the system always changes. 5. As ΔQ = 0 in this process, hence the molar heat capacity in such a process is C...

 What are adhesive and cohesive forces? Adhesive and cohesive force defined as: Adhesive force It is the force of attraction acting between molecules of two different materials. For example, the  force  acting between the molecules of water and glass. Cohesive force 1) It is the force of attraction acting between molecules of the same material. For example, the force acting between the molecules of water or mercury etc. 2) If cohesive force is large then the adhesive force, the liquid will not stick to the vessel containing it. It is so in case of mercury and glass. 3) If cohesive force is less than the adhesive force, the  liquid  will stick to vessel containing it. It is so in case of water and glass. Cohesive or adhesive force varies inversely as the eighth power of distance between the molecules. Adhesive and cohesive force Buoyant force or Buoyancy 1) It is an upward force acting on the body immersed in a liquid. 2) It...

What is application of Doppler effect? Application of Doppler effect - a)  To determine the direction of motion of stars with respect to earth: In astronomy, Doppler effect is used to determine whether a particular star or a galaxy is approaching the earth or moving away from the earth. Light from the star is observed with the help of a spectrometer. Several spectral lines are observed and these are compared with earth source. It has been generally found that the wave length of light received from the stars shifted slightly towards the red end of the spectrum. This is called RED SHIFT. It shows that the stars receding away from us and our universe are expanding. b)  To determine the speed of an approaching submarine using Doppler effect: Sound waves are transmitted in water from a ship towards the approaching submarine. The frequency of the reflected waves is measured by mean of a device, called SONAR...

What are atom Models? Thomson Atom Models Thomson Atom Models suggest an atom to be a tiny sphere of radius ≈ 10 -10  m, containing the positive charge. The atom is electrically neutral. It contains an equal negative charge in the form of electrons , which are embedded randomly in the sphere, like seeds in a water melon. This model failed to explain 1) Large angle scattering of a particles 2) Origin of spectral lines observed in the spectrum of hydrogen atom.                                                                                     Thomson Atom Models Rutherford atom models It was assumed that negatively charged  electrons  remove around the nucleus in circular or bits. The model failed because it predicted continuous atomic spectrum and...

Describe bending of a cyclist in circular motion? Bending of a cyclist in circular motion : 1. A cyclist while going round a curve on a horizontal track has to bend himself a little from his vertical position in order to avoided overturning. When he bends himself inward, a component of the reaction of road provides him the necessary centripetal force for circular motion . Bending of a cyclist in circular motion 2. In order to find the angle through which a cyclist has to bend himself to take a safe turn, let us assume that m= combined mass of cycle and cyclist v= uniform speed with which the cyclist takes the turn r=radius of circular track And θ = angle through which the cyclist bend from vertical 3. Suppose G represents the centre of gravity of the system (following figure shows). If force of friction between the cycle and the road is not taken into account, then following two forces act on the system at the point G. a) Weight mg of the sy...

Calculating distance and size of moon Distance of moon (reflection method) Using reflection method we will calculate the distance of moon. A laser beam is a source of very intense, monochromatic and unidirectional beam. By sending a laser beam towards the moon instead of sound waves , the echo method becomes useful in finding the distance of moon from earth. If t is the total time taken by laser beam in going towards moon and back, then distance s of moon from earth’s surface is given by: s = ct/2. Where c =3 × 10 8  m/s, is the velocity of light.   Calculation of size of an astronomical object like moon (Triangulation method) Calculating distance and size of moon Suppose moon be the astronomical object, whose diameter D is to be measured shown in the above figure. In order to do so, moon is observed with the help of a telescope from a place E on the earth and the angle θ made by two diametrically op...

How to calculate distance of submarines in sea and aero plane in sky? Calculating distance of submarine and aero plane in sky can be made by two following ways. Distance of submerged objects or submarines in sea (Sound Navigation and Ranging- SONAR) SONAR  is an instrument which uses ultrasonic  waves  (waves having frequency > 20, 000 Hertz) to detect and locate the submerged objects, submarines etc. in sea. Ultrasonic waves produced from a transmitter are sent towards the distant object under water. When the object comes in the direction of ultrasonic waves, then the waves are reflected back from it. Measuring the time interval t between the instant the ultrasonic waves are sent and received back, the  distance  s of the object can be calculated by the relation. s= ct/2 Where c is the  velocity  of ultrasonic waves Calculating distance of submarine and aero plane in sky Distance of aero plane in the sky (Radio Detecting and Rangin...

How to calculate height and distance of a hill? Calculating height and distance of a hill : The distance of hill can be calculated by using reflection or echo method. To find the distance of a hill , a gun is fired towards the hill and time interval t between the instant of firing the gun and the instant of hearing the echo of the gun is determined. Clearly, during this time interval sound first travels towards the hill from the place of firing and then back from the hill to the place of firing. If v is the  velocity  of sound, and s the distance of the hill from the place of firing, then. 2s= v × t  or  S= v t/2 Calculating height of a hill or height of an inaccessible object Sometimes, we come across a situation that it becomes impossible to measure the  distance  between the object and the observation point. The object is called an inaccessible object. Suppose, there is a mountain on the other bank on the other bank of a wide river...

What is centripetal force in circular motion? Centripetal force in circular motion: 1. According to Newton’s law of motion , whenever a body moves in a straight line with uniform velocity, no force is required to maintain this velocity. But when a body moves along a circular path with uniform speed, its direction changes continuously i.e., velocity keeps on changing on account of a change in direction. According to Newton’s second low of motion, a change in the direction of motion of the body can be place only if some external force acts on the body. 2. Due to inertia, at every point of the circular path; the body tends to move along the tangent in the circular path at the point shows in following figure. Since everybody has directional inertia, a velocity cannot change by itself and as such we have to apply a force. But this force should be such that it changes the direction of velocity and not its magnitude. This is possible only if the for...

Describe the collision between particles? Collision between particles is defined as : 1. The mutual interaction of the particle for a small interval of time due to which both the energy and momentum of the interacting particle change. 2. There are so many examples of collision from our day to day life e.g., collision between two gaseous  atoms  at room temperature. 3. It is not necessary for two bodies undergoing collision to have physical with contact with each other. In case of Rutherford’s α-particle scattering experiment, α-particles were scattered due to electrostatic interaction between α-particle and the nucleus separated by some  distance . Hence, in Physics a collision will take place if either of the two bodies comes in physical contact with each other or even when path of one body is affected by the force exerted due to the other. 4. Collision between two particles are broadly categorized into two types: A)  Elastic Col...

What is communication system? All modes of long distance communication system have been super ceded by electrical, electronic and optical modes. A communication system acts as a messenger. It consists of transmitter, communication channel and a receiver. A message signal has to be transformed appropriately to make it capable to transmission. The message signals for communication can be analog signals or digital signals. We cannot transmit an electronic signal in the audio frequency range (20 Hz to 20 kHz) over a long distance because. 1) The antenna or aerial should have a size comparable o the wavelength of signal (≈ 15 km)- which is too large. 2) Power of radiated 1/λ 2 . For good transmission, we need high powers and hence smaller wavelength or higher frequency. 3) Low frequency signals transmitted as such will get mixed up and there is no way to distinguish between them. Hence to transmit audio frequency signals, we use a high frequency signal called the carrier wave. The m...

What are conductors? Conductors are the materials which possess a large number of free charge carries and also bound charge carriers. Whereas Insulators or dielectrics possess a negligibly small number of  free electrons . When a conductor is placed in an external electric field, net electric field in the interior of a conductor is zero , there is no charge in the interior of a conductor i.e. charge always resides on the outer surface of the conductor. The surface of the conductor is an equipotential surface and electric field over a charged conductor is perpendicular to the surface of the conductor at every point. Conductors Capacitance of a capacitor is the ratio of charge (Q) Capacitance(c) of a capacitor is the ratio of charge (Q) given and the potential (V) to which it is raised i.e. C=Q/V. The value of C depends on size, shape and relative position of two coatings of the capacitor. It also depends on nature of medium separating the two coatings. Capacity of a para...

What is crystal? Crystal can be divided into following types:  Crystal Single crystal The crystal in which the periodicity of the pattern extends throughout the piece of the crystal are known as single crystal. Single crystal s have an isotropic behavior i.e. their physical properties (like mechanical strength, refractive index, thermal and electrical conductivity) are different along different directions. The small size single crystals are called mono-crystals. single crystal Poly-crystal A poly-crystal is the aggregate of the mono crystals whose well developed faces are joined together so that it has isotropic properties. Ceramics are the important illustrations of the poly-crystalline solids. Poly-crystal Liquid crystal The organic crystalline solid which on heating to a certain temperature range becomes fluid like but its molecules remain obtained in a particular directions, showing that they retain their anisotropic properties, is called liq...

What is dimension of a physical quantity? 1. In all the systems of units, the derived units of all the physical quantities can be expressed in terms of the  fundamental units  of mass, length and time, raised to some power. The powers to witch fundamentals units must be raised in order to express a physical quantity, are called its dimensions. To make it clear, consider the physical quantity density which is defined as mass per unit volume. Hence,  density=mass/volume=M/L 3 =[M1L 3 T 0 ]. Dimensions of a Physical Quantity 2. a) Above expression shows that dimensions of a physical quantity (density) are 1 in mass, -3 in lengths and 0 in time. c) Dimensional formula for density is [ML -3 ] or [ Ml -3 T 0 ]. d) Dimensional equation for density is [d] =[ML -3 T 0 ]. Dimensional formula of some physical quantities in mechanics and their units in different systems Physical Quantity Formula Dimensional Formulae S.I Unit Area Length × breadth [L 2 ] m 2 Vol...