Saved Bookmarks
| 1. |
Four charges of +q, +q, +q and +q are placedat the corners A, B, C and D of a square. Find the resultantforce on the charge at D. |
|
Answer» SOLUTION :Let SIDE= a, `BD=sqrt(2)a` force `F_(1)=(1)/(4pi in_(0)) . (Q^(2))/(a^(2)) ` (A to D) force `F_(2)=(1)/(4pi in_(0)).(q^(2))/(a^(2))` (C to D) `:. F_(1) = F_(2) =F`  RESULTANT of `F_(1) and F_(2)=sqrt(F_(1)^(2) +F_(2)^(2)) =sqrt(2).F` force DUE to charge at B is `F_(3) =(1)/(4pi in_(0)) .(q^(2))/((sqrt(2)a)^(2)) =(1)/(2) (1)/(4pi in_(0)) (q^(2))/(a^(2))` (B to D) Resultant force on change at `D=sqrt(2)F+F_(3)` `=sqrt(2) (1)/(4pi in_(0)).(q^(2))/(a^(2))+(1)/(2) (1)/(4pi in_(0)) .(q^(2))/(a^(2))` `=(1)/(4pi in_(0)) (q^(2))/(a^(2)) [sqrt(2) +(1)/(2)]=(q^(2))/(8pi in_(0) a^(2)).[1+2sqrt(2)]` |
|