JEE Advanced2014PhysicsElectrostaticsActual
Four charges Q 1 , Q 2 , Q 3 and Q 4 of same magnitude are fixed along the x axis at x = - 2 a , - a , + a and + 2 a , respectively. A positive charge q is placed on the positive y axis at a distance b > 0 . Four options of the signs of these charges are given in List I. The direction of the forces on the charge q is given in List II. Match List I with List II and select the correct answer using the code given below
Options
- Aa-r;b-p;c-q;d-s;
- Ba-q;b-s;c-r;d-p;
- Ca-s;b-q;c-r;d-p;
- Da-r;b-p;c-s;d-q;
Correct answer
D. a-r;b-p;c-s;d-q;
Step-by-step solution
P: By Q 1 and Q 4 , Q 3 and Q 2 F is in +y Q: By Q 1 and Q 4 , Q 2 and Q 3 F is in +ve x. R: By Q 1 and Q 4 , F is in +ve y By Q 2 and Q 3 , F is in -ve y But later has more magnitude, since its closer to (0, b). Therefore net force is in - y S: By Q 1 and Q 4 , F is in +ve x and by Q 2 and Q 3 , F is in -x, but later is more in magnitude, since its closer to (0, b). Therefore net force is in -ve x.