2. Solved Papers
  3. BCECE Medical

BCECE Medical BCECE Medical Solved Papers-2014

  • question_answer
    In photoelectric effect, if the energy required to overcome the attractive forces on the electron, (work functions) of Li, Na and Rb are 2.41 eV, 2.30 eV and 2.09 eV respectively, the work function of K could approximately be in eV.

    A)  2.52             

    B)  2.20

    C)  2.35

    D)  2.01

    Correct Answer: B

    Solution :

    As the size of atom (element) increases, energy required to overcome the attractive force on outermost electron decreases. Li, Na, K and Rb are the members of same group and have the following order of size                 \[Li<Na<K<Rb\] Thus, the energy in case of K is intermediate of Rb and Na, i.e.,                 \[2.30<K<2.09\] or the energy for K is 2.20 eV.


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