Question

In Thomson spectrograph experiment, four positive ions P, Q, R and S are situated on Y–X curve a shown in the figure. 

(A) The specific charge of R and S are same 

(B) The masses of P and S are same 

(C) The specific charge of Q and R are same 

(D) The velocities of R and S are same

Answer 1

The correct option is (A) The specific charge of R and S are same.

Explanation:

All the positive ions which have same (e/m) ratio i.e. same value of specific charge are focused on the same parabola on respective of their velocities. 

Hence (e/m) ratio i.e. specific change of R and S are same. Also it is same for P & Q.