A mass spectrograph (spectrometer) sorts out
1.molecules
2.ions
3.elements
4.isotopes
A particle having the mass of an electron and the charge of a proton is called a
1.antiproton
2.positron
3.gamma rays
4.photon
According to which one of following law the density of atom is uniform?
1.J.J.Thomson model
2.Rutherfords model
3.Bohrs model
4.all of above laws contradict the statement
An ?-particle is emitted from 88Ra226. What is the mass and atomic number of the daughter nucleus?
1.224 - 84
2.220 - 80
3.222 - 86
4.226 - 87
An OP-AMP comparator is a circuit that compares the signal voltage on one of its inputs with a _
1.Non-inverting voltage at output
2.Reference voltage on the other
3.Virtual input
4.Output
An OP-AMPs can amplify
1.D.C.
2.A.C.
3.Both A.C. & D.C.
4.None of the above
Antimatter consists of
1.antiproton
2.antineutron
3.positron
4.all of above
Average energy required to remove one nucleon from the nucleus is called
1.binding energy per nucleon
2.energy of decay
3.destruction energy
4.all of above
Charge on an electron was determine by
1.Ampere
2.Maxwell
3.Millikan
4.Thomson
Charge on neutron is
1.plus 1.6 x 10-19C
2.zero
3.minus 1.6 x 10-19C
4.no definite charge
Diameter of an atom is approximately
1.10-12m
2.10-11m
3.10-10m
4.10-14m
During an encounter with an atom ?-particle knocks out
1.protons
2.electrons
3.neutrons
4.nothing
During fission process a large amount of
1.heat energy is released
2.nuclear energy is released
3.chemical energy is released
4.light energy is released
During fusion of hydrogen into helium
1.energy is absorbed
2.energy is released
3.mass is increased due to energy absorption
4.mass is reduced due to energy released
Electrons
1.can exist inside the nucleus
2.cannot exist inside the nucleus
3.can exist both inside and outside the nucleus
4.do not know
Energy liberated when one atom of U-235 undergoes fission reaction is
1.200MeV
2.40MeV
3.30MeV
4.20MeV
Fission chain reaction in a nuclear reactor can be controlled by introducing
1.iron rods
2.graphite rods
3.cadmium rods
4.platinum rods
For chain reaction to build up the size of the radioactive target should be
1.greater than the critical size
2.less than the critical size
3.equal to the critical size
4.all of above can build up a change reaction
Half life of radium is 1590 years. In how many years shall the earth loss all its radium due to radioactive decay?
1.1590x106 years
2.1590x1012 years
3.1590x1024 years
4.never
If one or more of the neutrons emitted during fission cab be used to build up further fission then the reaction is self sustained and is known as
1.fission reaction
2.fusion reaction
3.chain reaction
4.chemical reaction
In forward bias the width of potential barrier
1.Increases
2.Decreases
3.Remains same
4.No effect
In liquid metal fast breeder reactor the type of uranium used is
1.92U235
2.92U238
3.92U234
4.92U239
In nucleus of uranium the number of neutrons will be
1.92
2.235
3.143
4.different for different isotopes
Mass defect per nucleon is
1.binding energy of nucleus
2.packing fraction
3.average energy of nucleus
4.all of above are one and same thing
Mass of neutron is
1.1.67 x 10-31 kg
2.1.67 x 10-27 kg
3.9.1 x 10-31 kg
4.1.67 x 10-19 kg
Neutron and proton are commonly known as
1.nucleon
2.meson
3.boson
4.quartz
Non-inverting amplifier circuits have
1.A very high input impedance
2.A very low input impedance
3.A low output impedance
4.None of the above
Nuclear forces exist between
1.proton-proton
2.proton-neutron
3.neutron-neutron
4.all of the above
Nuclei having the same mass number but different atomic number are
1.Isotopes
2.Isobars
3.Isotones
4.Isomers
One amu is equal to
1.1.66 x 10-27kg
2.166 x 10-15ng
3.166 x 10-20?g
4.all of above
Pair production takes place in the vicinity of a heavy nucleus so that
1.net energy is conserved
2.net charge is conserved
3.net momentum is conserved
4.all of the above
Radioactive decay obeys which one of the following law?
1.N=N?e-?t
2.N=N?e?t
3.N=N?e-?t/2
4.N?=N(1+e?t)
Radioactive materials can be identified by measuring their
1.hardness
2.density
3.mass
4.half life
Radioactivity is a ______ (A) Spontaneous activity (B) Chemical property
1.A & B
2.B & C
3.C & A
4.A B & C
Sterilization of surgical instruments medical supplies and bandages can be done by exposing them to a beam of
1.?-rays
2.?-rays
3.?-rays
4.b and c have equal antiseptic properties
Sum of the masses of constituent nucleons as compared to the mass of the resultant nucleus is
1.smaller
2.greater than 82
3.same
4.some times smaller some times greater
The bombardment of nitrogen with ?-particles will produce
1.neutron
2.Proton
3.electron
4.positron
The electronic circuits which implement the various logic operations are called
1.Logic gates
2.Boolean algebra
3.Amplifier gain
4.Logic functions
The operation of a transistor requires
1.That the emitter be heated
2.That the base be heated
3.That the collector be heated
4.None of the above
The path of ?-particle is
1.rectilinear
2.curved
3.zig-zag or erratic
4.elliptical
The unit of radioactivity curie is equal to
1.3.74 x 109 disintegration per sec
2.3.70 x 1010 disintegration per sec
3.3.55 x 1010 disintegration per sec
4.3.60 x 1010 disintegration per sec
The working of transistor as amplifier is similar to
1.Step up transformer
2.Step down transformer
3.Three diodes in common
4.Triode vacuum tube
Tick the correct statement
1.moderators slow down the neutrons
2.moderators bring the neutrons to rest
3.moderators absorb the neutrons
4.moderators reflect the neutrons
To obtain a p-type semi-conductor Si Crystal must be doped with foreign atoms whose valency is
1.2
2.3
3.4
4.5
To obtain an n-type semiconductor germanium crystal it must be doped with foreign atoms whose valency is
1.2
2.3
3.4
4.5
Transuranic elements have atomic number
1.greater than 72
2.greater than 82
3.greater than 92
4.greater than 102
Various types of cancer are treated by
1.cobalt-60
2.strontium-90
3.carbon-14
4.nickel-63
Which of the following radiations are suitable for the treatment of an infection in the interior of the body ?
1.?-rays
2.?-rays
3.?-rays
4.X-rays
Which one of the following radiation possesses maximum penetrating power?
1.?-rays
2.?-rays
3.?-rays
4.all have equal penetrating power
Which one of the following radiations possesses maximum velocity?
1.?-rays
2.?-rays
3.?-rays
4.all of above have same speed