question_answer 39)

Calculate the wavelength of an electron moving with a velocity \[2.05\times {{10}^{7}}m{{s}^{-1}}.\]

Answer:

We know, \[\lambda =\frac{h}{m\upsilon }\,\,\,\,\,\,\,\,\,\,\,\,\,\,......(i)\] where, \[h=6.626\times {{10}^{-34}}J\,\sec \] \[m=9.1\times {{10}^{-31}}kg\] \[\upsilon =2.05\times {{10}^{7}}m{{s}^{-1}}\] Putting these values in Eqn. (i), we get \[\lambda =\frac{6.626\times {{10}^{-34}}}{9.1\times {{10}^{-31}}\times 2.05\times {{10}^{7}}}\] \[=3.55\times {{10}^{-11}}m\]