Question

Two parallel conducting plates, each of area A, are separated by a distance d. Now, the left plate is given a positive charge Q. A positive charge q of mass m is released from a point near the left plate. Find the time taken by the charge to reach the right plate.

• A. $\sqrt{\frac{3dm{\epsilon }_{0}A}{qQ}}$
  
• B. $\sqrt{\frac{4dm{\epsilon }_{0}A}{qQ}}$
  
  
• C. $\sqrt{\frac{2dm{\epsilon }_{0}A}{qQ}}$
  
  
• D. Given information is insufficient

Answer 1

The correct option is B $\sqrt{\frac{4dm{\epsilon }_{0}A}{qQ}}$



$E=\frac{Q}{2A{\epsilon }_0}a=\frac{qE}{m}=\frac{qQ}{2Am{\epsilon }_0}d=\frac{1}{2}a{t}^2;t=\sqrt{\frac{2d}{a}}=\sqrt{\frac{2d2Am{\epsilon }_0}{qQ}}$