Ranking of de Broglie wavelengths from largest to smallest is electron > proton > helium
De Broglie's relationship is given by .....(1) , where λ is known as de Broglie wavelength and m is mass , v is velocity , h = Plank’s constant.
From equation (1) wavelength and mass has an inverse relation .
Mass of helium is 4 times the mass of the proton and proton has a greater mass than electron.
According to equation (1) , less the mass higher will be the wavelength
Hence electron having less mass have higher wavelength and then proton and then helium having large mass will have less wavelength .
Thus, order should be electron > proton > helium .
Learn about de brogile wavelength more here :
#SPJ4
See this suggested solution.
1. Let a force F' is the vector sum of the forces P and Q, then it is shown on the attached picture and marked with red color.
2. according to the condition the force F holds the object, then F should have the same length as the force F' and the opposite direction.
3. using the conditions described in 2. the answer is C.
