# three metallic plates a,band c carrying charges +Q,-2Q and +3Q are placed parallel to each other,where plate a and b are at a distance 'd' and b and c are at a distance '2d'.plate a and c are connected by a switch 's'.determine the charge appearing on each plate when switch 's' is closed and the charge flown through the the switch.

10 years ago
Use the simple concept of distribution of charge , and two paraller plates makes a capacitor, arrange the charges accrodingly.

sher mohammd
b.tech, iit delhi
Arun Kumar IIT Delhi
10 years ago
Hi

Let's say three plates charges Q1,Q2,Q3
We find equations by assuming electric field in the conductor zero.
Charges are conserved on each plate.

$Q_{a,left}=Q_{c,right}\\ Q_{a,right}+Q_{b,left}=0\\ Q_{b,right}+Q_{c,left}=0\\ Q_{a,left}+Q_{a,right}=Q1 \\Q_{b,left}+Q_{b,right}=Q2 \\Q_{c,left}+Q_{c,right}=Q3 \\adding\,all=>Q_{a,left}=(Q1+Q2+Q3)/2=Q_{c,right}=-Q/2 \\=>Q_{c,left}=Q3-Q_{c,right}=(Q3-Q2-Q1)/2=-3Q/2 \\=>Q_{b,right}=-Q_{b,left}=3Q/2 \\=>Q_{a,right}=-3Q/2$

Thanks & Regards, Arun Kumar, Btech,IIT Delhi, Askiitians Faculty