NEET-XII-Physics

44: X-rays

with Solutions - page 2
Qstn# ii-12 Prvs-QstnNext-Qstn
  • #12
    50% of the X-ray coming from a Coolidge tube is able to pass through a 0.1 mm thick aluminium foil. The potential difference between the target and the filament is increased. The thickness of the aluminium foil that will allow 50% of the X-ray to pass through will be
    (a) zero
    (b) < 0.1 mm
    (c) 0.1 mm
    d) > 0.1 mm
    digAnsr:   d
    Ans : (d) > 0.1 mm
    As we increase the accelerating potential between the filament and the target, the penetrating power of the X-ray will increase. As a result, the fraction of the X-ray passing through the foil will increase. But it is given that the same fraction of the X-ray is passing. Therefore, the thickness of the aluminium foil should be increased to maintain the same fraction of the X-ray that will pass through the foil.
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