Duduli

Tandem accelerator is a modified form of Van de graaff accelerator.The Van de graaff accelerator is a single stage accelerator while Tandem accelerator is a two stage accelerator.The output energy is double in comparison of Van de graaff accelerator with the same operating voltage.

Van de graaff generator is used to produce a parallel homogeneous beam of charged particles like electrons, protons,α-particles etc. It was developed by van de graaff in 1931 at Princeton university, USA. Principle :- The instrument is based on the following two facts: (i) If a charged conductor is brought into internal contact with a hollow conductor, all of its charge transfers to the hollow conductor, no matter how high is potential of the latter. (ii) The discharge of electricity  occurs readily at pointed objects (corona points).

According to shell model the nucleus consists of protons and neutrons which are placed in certain discrete levels or shells just like the electrons in the discrete shells of an atom.

The phenomenon of spontaneous emission of radiations from the elements much lighter than those occuring in nature by modern techniques of artificial transmutation of elements is known as artificial or induced Radioactivity.

The phenomenon of spontaneous emission of powerful radiations exhibited by the heavier elements found in nature is called natural Radioactivity.

According to tunnel effect, if a particle is impinging (means strike) on a barrier, with energy less than the height of the potential barrier, it will not necessarily be reflected by the barrier but there is always a probability to cross the barrier and continue its forward motion.

The range of α-particles is customarily defined as the distance which these particles travel through air at 76cm of mercury pressure and 15°C temperature before they lose their energy to the extent that they no longer ionise the gas particles. ★The range of α-particles depends upon the following factors (i) Initial velocity of α-particle (ii) Nature of emitting radioactive element (iii) Nature & pressure of the gas or nature of absorber.

The following conservation laws must be obeyed for α-decay ★Conservation of charge and number of nucleons ★Conservation of linear momentum ★Conservation of mass-energy       The alpha decay may be represented as:

It has been observed that the mass of a stable nucleus is less than sum of masses of the constituent nucleons (proton & neutrons).           I.e       Real nuclear mass, M<(Zmp+Nmn) The difference between the sum of the masses of nucleons constituting the nucleus and real mass of nucleus is known as mass defect. ★ Mass defect, ∆m=[(Zmp+Nmn)]–M     Where, mp=mass of proton                 mn=mass of neutron                 Z=number of protons                 M=mass of nucleus                 N=number of neutrons

Some radioactive substances emit beta particles which produce line spectra (Discrete spectrum) superimposed on the continuous faint background.These are called also secondary spectra.

A process is said to be quasistatic process if variables takes place in such a slow rate that P,V & T remains constant.

Intensity of magnetic field or strength of magnetic field at any point is defined as the force experienced by a unit north pole placed at that point. →It is denoted by B                     B=F/m Where, F=magnetic force             m= north pole strength

Electric current through a wire results in the production of heat that means energy.This phenomenon is called heating effect or thermal effect of Electric current.

The limit of a function is the most fundamental concept in the study of calculus as well as of Mathematical analysis. ★ Limit:- let f(x) be a given function then limit of f(x) at x=a is denoted by limit x→a f(x) (1) left hand limit:-  let f(x) be a given function then left hand limit of f(x) at 'a' is limit x→a- f(x)=limit h→0 f(a-h) (2) Right hand limit:-  Similarly right hand limit of f(x) at 'a' is limit x→a+ f(x)=limit h→0 f(a+h) ★ Existence of limit at a point:- Limit h→0 f(a-h)=limit h→0 f(a+h)=limit  x→a f(x)

Consider an example :- Emission of radiation by an electron when it jump from higher energy state to lower energy state produces a light burst.Each light burst occurs over a period of 10-⁸s only, during which period a train of finite length having a certain limited number of wave oscillations is generated.such a light burst is known as a wave train or a wave packet.

Communication system is a system which consist of transmitter, communication channel & receiver. →A block diagram of a generalised communication systemn is shown as below ★ Transmitter:- It consists of transducer/signal generators,modulators, Amplifier & transmitting antenna. ★ Communication channel:- The physical path between the transmitter & receiver is known as communication channel. ★ Receiver:- Its main function involves picking up the signals, demodulating, amplifying & displace the original message signal.

The cylinder is a surface generated by a variable straight line which is parallel to a fixed line and intersecting a given curve. It has following parts↓ (i) Generator:- The line which generates the surface of the cylinder. (ii) Axis:- The fixed straight line is called the axis. (iii) Guiding curve:- The curve with which the generator intersect. ★Equation of cylinder The equation of Cylinder whose generators are parallel to the line x/l=y/m=z/n and base is the conic is ax²+by²+2hxy+2gx+2fy+c=0,z=0

The total amount of work done in making an assembly of charges by bringing them from infinity to their respective places is called electric potential energy due to system of charges.

The rate of change of direction of a curve with respect to distance along the curve is called curvature.  It is denoted by k .                          K=dψ/ds Where ψ represent angle of contingence.                       

Asymptote is a straight line which touches the curve y=f(x) at infinity.                             ||Or|| A straight line is said to be an asymptote of an infinite branch of a curve, if as the point p recedes to infinity along the branch, the perpendicular distance of p from the straight line tends to zero.

Time constant for RC circuit is defined as the product of Resistance (R) & Capacitance (C).       I.e t=RC 

Time constant of RL circuit is defined as the ratio between co-efficient of self induction (L) to the resistance (R).       I.e t=L/R