NEET-XII-Physics

44: X-rays

with Solutions - page 2
Qstn# ii-5 Prvs-QstnNext-Qstn
  • #5
    If the current in the circuit for heating the filament is increased, the cutoff wavelength
    (a) will increase
    (b) will decrease
    (c) will remain unchanged
    (d) will change
    digAnsr:   c
    Ans : (c) will remain unchanged
    Cut off wavelength is given by
    `` {\lambda }_{\,\mathrm{\,min\,}}=\frac{hc}{eV}``,
    where h = Planck's constant
    c = speed of light
    e = charge on an electron
    V = potential difference applied to the tube
    Clearly, the cutoff wavelength does not depend on the current in the circuit and temperature of the filament.
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