Verified Solution • 2025–26 Session moderate

QJEEM19Ph04c8: JEE Main 2019 Physics - Class 12 JEEM19Ph04c8 Solution: If the de Broglie wavelength of an electron is equal to the 10…

If the de Broglie wavelength of an electron is equal to the 10–3 times the wavelength of a photon of frequency 6 ×\times 1014 Hz, then the speed of electron is equal to : (Speed of light = 3 ×\times 108 m/s, Planck's constant = 6.63 ×\times 10–34 J.s, Mass of electron = 9.1 ×\times 10–31 kg)

Multiple Choice Options

  • A 1.7 ×\times 106 m/s
  • B 1.45 ×\times 106 m/s
  • C 1.1 ×\times 106 m/s
  • D 1.8 ×\times 106 m/s

Step-by-Step Verified Solution

hmv=10−3(3×1086×1014){h \over {mv}} = {10^{ - 3}}\left( {{{3 \times {{10}^8}} \over {6 \times {{10}^{14}}}}} \right)

v =6.63×10−34×6×10149.1×10−31×3×105= {{6.63 \times {{10}^{ - 34}} \times 6 \times {{10}^{14}}} \over {9.1 \times {{10}^{ - 31}} \times 3 \times {{10}^5}}}

v =1.45×106= 1.45 \times {10^6} m/s

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