Physics Tutors in Delhi University, Delhi

A cyclotron is a particle accelerator. It is an electrically powered machine which produces a beam of charged particles that can be used for medical, industrial and research processes. As the name suggests, a cyclotron accelerates charged particles in a spiral path, which allows for a much longer acceleration path than a straight line accelerator.

A cyclotron body consists of electrodes, called 'dees' because of their shape, in a vacuum chamber. This vacuum chamber is flat and sits in a narrow gap between poles of a large magnet which creates a perpendicular magnetic field. A stream of charged particles is fed into the centre of the chamber and a high frequency alternating voltage is applied across the electrodes. This voltage alternately attracts and repels the charged particles causing them to accelerate.

The magnetic field moves the particles in a circular path and, as they gain more energy from the accelerating voltage, they spiral outwards until they reach the outer edge of the chamber.

Modern cyclotrons accelerate negative ions created in a plasma. When these negative ions reach the outer edge of the chamber the excess electrons are stripped off the ions forming positive particles such as a proton or deuteron, which can then be extracted from the cyclotron as a beam. The size of the vacuum chamber determines the length of the spiral path and hence the amount of energy attained by the particle.

Medical cyclotrons

Medical cyclotrons produce proton beams which are used to manufacture radioisotopes used in medical diagnosis. Radioisotopes produced in a cyclotron decay by either positron emission or electron capture. Positron emission tomography (PET) and single photon emission computed tomography (SPECT), which utilises the gamma rays associated with electron capture, are two imaging techniques that rely on cyclotron-produced radioisotopes.

Because metals have free Or mobile electrons thats why they conduct electricity.In metal, the outer most orbit of an atom of that metal having electrons which is losely bond with the atom.If we give the electric current in that metal, the elctron which is in the outermost orbit moves from that atom and collides with the positive charged ions in the metal conductor.Hence the drifting of electrons takes place.

Electrons moves from lower potential to higher potential where as electric current moves from higher potential to lower that is just opposite direction of electron

So electrons moves from lower to higher potential with drift in its motion and current moves just opposite direction of electron. From this the electrons and current makes its own path in the metal and flow from one end to another end, the electric current pass from that metal that is the metals conducts electricity.

Metals are good conductor of heat as well as electricity because of its free electrons.

Ans. Option B) to decrease the pressure on the ground

Reason: Caterpillar tracks make greater surface area of contact with the ground. We know, greater the area of contact, lower the pressure exerted.

The major source of ultravoilet rays happens to be the sun. However mintute amount of rays are also recieved from sources such as exploding stars, stars from other galaxies etc.

Both type of majority carriers

'' Time period of given SHM is 3 sec. 3 sec in the scence 2*pi/(2*pi/3). So time taken to reach from mean to extreme is one fourth of time period. So 3/4 sec will be taken.

If you are talking about stopping potential then it must increase because to stop high energy electrons we have to apply high opposing potential.

measured by odometer

It can be ductible malleable and can be mixed through others easily