What is ultrasonics? The study and application of mechanical vibrations with frequencies beyond the limits of hearing of the human ear i.e ,with frequencies about 20 kHz and upwards.There is no theoretical upper limit to the ultrasonic frequency ,although ultrasonic applications are usually restricted to about 20 MHz.Ultrasonic waves have the same basic properties as sound waves,both being examples of ...

Read More »## Hall effect and its applications in semiconductors

“An effect when occurring when a current carrying conductor is placed in a magnetic field and orientated so that the field is at right angles to the direction of the current.”This is the Hall effect, named after E. H. Hall who discovered it in 1879.The difference of potential produced is called the Hall emf. An electric field is produced in ...

Read More »## Does the sun do any work on earth?

No work is done on the earth revolving around it in perfectly circular orbit.The earth revolves around the sun due to gravitational force of attraction between the sun and the earth.This gravitational force provides centripetal force to the earth to revolve around the sun.Since centripetal force is always directed towards the centre of the orbit.This centripetal force is always perpendicular ...

Read More »## Is energy quantized in classical physics?

No,according to classical wave theory the emission of electromagnetic radiations from the surface is continuous. So energy is not quantized in classical physics.But according to photon theory the emission of electromagnetic radiation from the surface is discontinuous.Energy is quantized and radiations are emitted in the form of bundles of energy is called quanta or photon.Each photon has energy given as: ...

Read More »## Types of radioactive decay:Alpha,beta and gamma decay

What is radioactive decay? “Radioactive decay is the process by which the nucleus of an unstable atom loses energy by emitting radiation, including alpha particles, beta particles, gamma rays and conversion electrons.” Most of the nuclides that have been identified are radioactive.That is,they spontaneously emit a particle,transforming themselves in the process into a different nuclide . In this section we discuss the two ...

Read More »## Ampere’s law and its applications in daily life

What is ampere’s law? According to this law “The line integral of magnetic field B along a closed path due to current is equal to the product of the permeability of free space and the current enclosed by the closed path”. Mathematically it is expressed as: Where μ0=permeability of free space i=current flowing through the conductor. Proof: Consider a straight ...

Read More »## gravitational potential energy : Definition,formula and examples

Gravitational potential energy is defined as the “energy of an object due to Earth’s gravity”.OR it is the product of objects weight and height.It is the most common example of P.E. Its formula is: W = mgh It means the higher an object the higher will be its Gravitational P.E. Examples of gravitational potential energy in everyday life ...

Read More »## Viscosity : Definition,formula,applications and Poiseuille’s law

What is Viscosity? “Viscosity is the internal friction in a fluid.”Viscous forces opposes the motion of one portion of a fluid relative to another.Viscosity is the reason it takes effort to paddle a canoe through calm water,but it is also the reason the paddle works.Viscous effects are important in the flow of fluids in pipes,the flow of blood,the lubrication of ...

Read More »## Work energy theorem derivation:examples and problems

Work energy theorem states that:“The net work done by the forces acting on the body is equal to the change in kinetic energy of the body.”Mathematically it is expressed as: Wnet = Kf –Ki = ∆k An unbalanced force applied to a particle will certainly change the particle’s state of motion. Newton’s second law provides us with one way to analyze this change ...

Read More »## Bernoulli equation derivation with examples and applications

Bernoulli equation definition Bernoulli’s equation is defined as:”The sum of pressure,the kinetic and potential energies per unit volume in a steady flow of an in compressible and non viscous fluid remains constant at every point of its path.”Mathematically it is expressed as: Bernoulli’s principle formula P+ ρgh +1/2 ρv2 =constant Bernoulli’s equation,which is a fundamental relation in fluid mechanics,is not a new ...

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