2. Sample Papers
  3. NEET

NEET Sample Paper NEET Sample Test Paper-36

  • question_answer
    An electron is moving round the nucleus of a hydrogen atom in a circular orbit of radius r. The coulomb force \[\vec{F}\]between the two is (where\[K=\frac{1}{4\pi {{\varepsilon }_{0}}}\])

    A) \[-K\frac{{{e}^{2}}}{{{r}^{3}}}\hat{r}\]

    B) \[K\frac{{{e}^{2}}}{{{r}^{3}}}\vec{r}\]

    C) \[-K\frac{{{e}^{2}}}{{{r}^{3}}}\vec{r}\]

    D) \[K\frac{{{e}^{2}}}{{{r}^{2}}}\hat{r}\] 

    Correct Answer: C

    Solution :

     \[\vec{F}=-k\frac{{{e}^{2}}}{{{r}^{2}}}\hat{r}=-k.\frac{{{e}^{2}}}{{{r}^{3}}}\vec{r}\] \[\left( \because \,\hat{r}=\frac{{\vec{r}}}{r} \right)\]


You need to login to perform this action.
You will be redirected in 3 sec spinner