In the present era, internet has become one of the indispensable part of our life. Most of us cannot think of is spending even one day without internet. Internet is a worldwide, publicly accessible services of interconnected computer networks that transmit data by packet switching, using standard internet protocol (IP). At the eve of international internet day it will be interesting to know some historical background about internet.
Great things were happening in the world in 1969, one of this is the event when a student programmer Charley Kline, at the UCLA has transmitted the first-ever message on 29th October 1969. This event was to follow only few months after the first man landed on the Moon. Charley Kline, working under the supervision of of Professor Leonard Kleinrock, transmitted a message from the computer housed at the UCLA to a computer positioned at the Stanford research institutes computers.
At the time when history was being made, internet was known as ARPANET (advanced research projects agency network).
Since 2005, the international internet day has been famously celebrated every year on the 29th of October to commemorate a momentous day in the history of telecommunications and Technology. Today the international internet day is also an online project germinating from the society of from the society, of the society and for the society. The internet is open and free for everyone. The international internet day thus celebrated this Grand democratic fervor which in essential is linked to this idea of liberation, where everyone is afforded an equal opportunity and an equal advantage to share of services, which connect the world to each other.
It is used for
acceleration of electrons (beta particles).
It employed no electric
field.
It employed changing
magnetic field which produce an induced e.m.f. which is responsible for the
acceleration of electrons.
4. Electron
Cyclotron
5. Proton
Cyclotron
6. Alternating
Gradient Cyclotron
7. Omnitron
Geiger-Muller Counter-
It based on the principle that gases
becomes electrical conductors due to ionization produced by their exposure to
radioactive or nuclear radiation.
MCQS
1: The angular frequency of a cyclotron is
independent of
(a) Speed
(b) Mass
(c) Magnetic field
(d) Charge
Answer: (a)
2: The maximum kinetic energy of the
positive ion in the cyclotron is
(a) qBR2/2m
(b) q2B2R2/2m
(c)
q2B2R2/m
(d) qBR/m
Answer: (b)
3: Cyclotron cannot accelerate
(a) Electrons
(b) Neutrons
(c)Positive ions
(d) Both
(a) and (b)
Answer: (d) Both (a) and (b)
4: The cyclotron frequency of an electron
grating in a magnetic field of 1 T is approximately
(a) 28 MHz
(b) 280 MHz
(c)2.8 GHz
(d) 28 GHz
Answer: (d)
5: Suppose a cyclotron is operated at an
oscillator frequency of 12 MHz and a dee radius of 53cm. What is the resulting
kinetic energy of the deuterons?
(a)16.6 MeV
(b) 12 MeV
(c)15 MeV
(d) 14 MeV
Answer: (a)
6: Cyclotron can be used in
(a)Particle therapy to treat cancer
(b)Source of high energy beam for a nuclear physics experiment
(c)Produce short-lived positron-emitting isotopes for PET imaging
(d)All the above
Answer: (d)
7: A proton of energy 100 eV is moving
perpendicular to a magnetic field T.
The cyclotron frequency of the proton in radian/sec
(a) 2.80 x 106
(a) 9.6
x 103
(c)5.6 x 106
(d) 1.76
x 106
Answer: (b)
8: A cyclotron can accelerate
(a)β particles
(b) α
particles
(c)High-velocity gamma rays
(d) High-velocity X-rays
Answer: (b)
9: Which of the following is preferred for
accelerating electrons?
(a)Betatron
(b) Cyclotron
(c)Synchrotron
(d) None of above
Answer: (b)
10: How much pressure is in metal chamber
of Geiger Muller Counter?
(a)100 atm
(b) 0.1 atm
(c) 10 atm
(d) 1 atm
Answer: b
11: Which of the following is cyclic
accelerator?
(a)
betatron
(b) synchrocyclotron
(c) synchrotron
(d) all of these
Answer: d
12: Which of the following accelerate the
particles in cyclotron?
(a)
Electric field
(b)
Magnetic field
(c) Both (a) and (b)
(d) None of
these
Answer: a
13: Which of the following deflects the
particle in cyclotron?
(a)
Electric field
(b) Magnetic field
(c) None of these
(d) Both (a) and (b)
Answer: b
14: Betatron works on the principle of
(a) Superposition
(b)
Ampere’s law
(c) electromagnetic induction
(d) self-induction
Answer: c
15: In betatron, the electron moves in
orbit
(a) of constant radius
(b) of variables
radius
(c) of radius as r2
(d) of radius
as (1/2)r
Answer: a
16: In Betatron, the electrons are
injected during
(a) decreasing magnetic field
(b) peak magnetic field
(c) increasing magnetic field
(d) zero magnetic field
Answer: c
17: The vacuum chamber are coated with
silver to
(a) avoid any insulation
(b) avoid eddy
currents
(c) increase the conductivity
(d) none of these
Answer: b
18: For proton acceleration up to 30 GeV,
which of the following is used?
(a) Cyclotron
(b) Betatron
(c) Betatron
(d)
Cosmotron
Answer: d
19: In synchrocyclotron, the frequency is
(a) varied
(b)
kept constant
(c) varies as q 2
(d)
varies as r 2
Answer: a
20: ‘When nuclear radiations pass through
the counter, gas ionization is produced.’ This is the principle of which of the
following detectors?
(a) Proportional counter
(b) Flow counter
(c) Geiger Muller counter
(d) Scintillation counter
Answer: c
Explanation: ‘When
nuclear radiations pass through, gas ionization is produced.’ This is the
principle of which of Geiger Muller counter. It is used to measure the intensity
of radioactive radiation.
21: Which of the following acts as
quenching gas in G.M. counter?
(a) Alcohol
(b)
Argon gas
(c) Krypton
(d) Hydrogen
Answer: a
Explanation: Alcohol acts
as quenching gas in G.M. counter. It is present in a gas tight envelope along
with the electrodes.
22: Which of the following acts as
ionising gas in Geiger Muller (G.M.) counter?
(a) Alcohol
(b)
Argon gas
(c) Krypton
(d) Hydrogen
Answer: b
Explanation: Argon gas acts as an ionising
gas in G.M. counter. It is present in a gas type envelope along with the
electrodes.
23: Geiger counter is a device to detect
(a) Mass
(b) Momentum
(c) Charge
(d) Radiation
Answer: d
24: Normally G. M. counter uses potential
different of
