Neet Solved Paper 2013 Question 1

Question: The value of Plancks constant is $ 6\text{.63 }\times\text{ 1}{0^{\text{-34}}}Js\text{.} $ The speed of light is $ \text{3 }\times\text{ 1}{0^{17}}nm{s^{\text{-1}}}\text{.} $ Which value is closest to the wavelength in nanometer of a quantum of light with frequency of $ \text{6 }\times\text{ 1}{0^{15}}{s^{\text{-1}}}? $

Options:

A) 10

B) 25

C) 50

D) 75

Show Answer

Answer:

Correct Answer: C

Solution:

  • Given, Plancks constant, $ h=6.63\times {10^{-34}}\text{J-s} $ Speed of light, $ c=3\times 10^{17}nm,{s^{-1}} $ Frequency of quanta $ v=6\times 10^{15}{s^{-1}} $ Wavelength, $ \lambda =? $ We know that, $ v=\frac{c}{\lambda } $ or $ \lambda =\frac{c}{v} $ $ =\frac{3\times 10^{17}}{6\times 10^{15}} $ $ =0.5\times 10^{2},nm $ $ =50,nm $