# Three identical metallic plates A,B and C are initially given charges Q,4Q,2Q respectively. If the plates A and C are connected by a conducting wire and plate B is earthed ,then how much charge flows from earth to plate B.

23 Points
8 years ago
A and C are connected, so charges on each will become (Q+2Q)/2= 1.5Q
B will be eartherd so -4Q charge will flow from earth to B and B will become chargeless

Thanx

23 Points
8 years ago
-4Q charge will flow from earth to sphere B

thanx
Akshay
11 Points
2 years ago
Lol no dude Rahbar Ahmed
That's not how you these types of questions
Better to get conceptual clarity rather than just mugging things up
Akshay
11 Points
2 years ago
We know A and C plates form an isolated system so the sum Qa + Qc=3 Q
Now taking B as an isolated system using we know the potential on B is zero hence we can use the formula for potential to get another relation between Qaand Qc
Now equate potentials of plates A and C to get final charge on plate B(QB)
Now 4  Q- QB will fetch you the required answer