Oct 28, 2008
Purpose: Cyclotron is a device used to accelerate heavy charge particles e.g.protons,deuerons etc.
Principle: It is based on the principle that a changed particle can be accelerated to very hagh energies by making it pass through a moderate electric field a number of times and applying a strong magnetic field at same time.
2-Two dees D1&D2 (D shaped hollow semi circular copper chambers called dees).
3-Source of high voltage coupled with adjustable high frequency oscillator.
4-Source of charged ions at the centre of the dees.g. deuterium for protons,helium for a-particles,bombarded with high energy electrons.
The hole assembly is housed in a vaccum chamber which is evacuated to a pressure of about 10-6 mm Hg,to avoid collision of charged particlels with medium gas particles which would result in loss of energy.
Oct 26, 2008
It is an instrument to detect and measure the strength of small electric current.
Principle:--When a current carrying coil is placed in magnetic field,it is experience a torque.
Construction:-It is consists of a coil bound on a non-magnetic field.The coil is suspended between two poles of a permanent magnet which are concave in shape.the coil is suspended by a phosphur bronze strip and this strip is connected to the terminal T1 of the galvanometer and other end of the coil is connected to hair spring which is connected to terminal T2 .A peace of the soft iron is the placed within the frame of the coil.A concave mirror is attached to the suspension to note the deflection of the coil using length and scale arrangement.
Fleming Left Hand Rule describes that if took the first three fingers of your hand so that Center Finger point to Current, First Finger point to the direction of Field then Thumb will point the Force.
A simple rule to remember this
Center Finger --> Current Direction
First Finger --> Magnetic Field Direction
Thumb(Most Powerful in hand) --> Force