The greatest power of ionization is in

  • alpha particles
  • gamma particles
  • beta particles
  • none of above

The radiations bend in the opposite direction in the magnetic field are

  • α and β radiations
  • α and γ radiations
  • γ and β radiations
  • all of above

The SI unit for radioactivity is

  • farad
  • Pascal
  • Becquerel
  • ammeter

The activity of 1 g of radium is

  • 3.73 * 104MBq
  • 2.76 MBq
  • 3.0 MBq
  • 5.9 MBq

When a heavy nucleus such as U-235 splits or fissions into two smaller nuclei by absorbing a small moving neutron, there takes place a

  • nuclear fission
  • nuclear power
  • nuclear transmutation
  • nuclear fusion

Per year safe limit of radiation exposure is

  • 5 rem
  • 10 rem
  • 7 rem
  • 15 rem

When alpha and beta particles are slowed down by collisions, they become

  • harmful
  • harmless
  • useful
  • expensive

Cosmic radiations interact with atoms atmosphere to create

  • primary radiation
  • secondary radiation
  • tertiary radiation
  • no radiation at all

The spontaneous emission of radiation by unstable nuclei is called

  • positive radioactivity
  • artificial radioactivity
  • natural radioactivity
  • negative radioactivity

The radiation that does not change its direction inside the magnetic field is

  • alpha
  • beta
  • gamma
  • x-ray

The half-life of &15&3N is 6.5 s. A sample of this nuclide of hydrogen is observed for 32.5 s. The fraction of the original radioactive isotope remaining after this time is

  • 1 ⁄ 32
  • 1 ⁄ 16
  • 1 ⁄ 8
  • 1 ⁄ 4

The radiation which does not change its direction is

  • β radiation
  • α radiation
  • γ radiation
  • no radiation

The activity of a sample of radioactive bismuth decreases to one-eighth of the original in 15 days. Its half-life is

  • 10 days
  • 15 days
  • 3 days
  • 5 days

Radioisotope for treating cancer tumors and cells is

  • Phosphorous-32
  • carbon-14
  • cobalt-60
  • cobalt-59

The strength of radiations to penetrate a certain material is known as

  • splitting power
  • ionization power
  • penetrating power
  • radiation power

The half-life of carbon-14 is

  • 1359 years
  • 4860 years
  • 5730 years
  • 2890 years

Times a proton is heavier than an electron is

  • 1827
  • 1876
  • 1836
  • 1789

The temperature at the center of the Sun is nearly

  • 20 million Kelvin
  • 10 million Kelvin
  • 30 million Kelvin
  • 25 million Kelvin

Ashes from a fire in the forest show carbon-14 activity of only 1/8 the activity of fresh wood. How long ago the forest had fire?

  • 18590 years
  • 17190 years
  • 16580 years
  • 14820 years

In the atmosphere, a small amount is present of radioactive

  • carbon-15
  • carbon-19
  • carbon-10
  • carbon-14

Radiation that causes redness and sores on the skin is

  • gamma only
  • beta only
  • alpha
  • gamma and beta

The radiations emitted by different elements are

  • alpha
  • beta
  • gamma
  • all of above

The artificially produced radioactive elements are known as

  • ions
  • radiant
  • radioisotopes
  • transmutations

The rate of radioactive decay is proportional to the number of

  • unstable nuclei
  • unstable protons
  • unstable electrons
  • unstable atoms

The release of energy from the sun is due to

  • nuclear fission
  • nuclear fusion
  • burning of gases
  • chemical reaction

In fission, the mass of products is

  • less than original nucleus
  • more than original nucleus
  • equal to original nucleus
  • all of above

The radiation which strongly interacts with the matter due to its charge and has a short-range as compared to gamma radiations is

  • alpha radiation
  • beta radiation
  • no radiation
  • gamma radiation

The number of protons and neutrons in the nucleus is called

  • neutron number (N)
  • atomic number (Z)
  • atomic mass number (A)
  • electron number (E)

In alpha decay (α-decay) the proton number of the parent nuclide

  • increases by 2
  • increases by 1
  • decreases by 2
  • decreases by 4

In the air, the beta particle has a range of

  • few centimeters
  • several thousand meters
  • several hundred meters
  • several meters
0 h : 0 m : 1 s

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