ElectrostaticsMedium

Question

Figure shows a system of three concentric metal shells A, B and C with radii a, 2a and 3a respectively. Shell B is earthed and shell C is given a charge Q. Now if shell C is connected to shell A, then the final charge on the shell B is equal to :

Options

A.−
B.−
C.−
D.−

Solution


(B)    Let q1 and q2 are charges on A and B respectively
From given conditions: Charge on A & C after connection with wire are q1 and Q − q1 on B, charge is q2
VA = VC and VB = 0
⇒  VB = + = 0
⇒  2Q + q1 + 3q2 = 0    .... (1)
Using VC = VA
+ =
⇒ q1 = −     .... (2)
Using it in (1),   q2 = − Q

Create a free account to view solution

View Solution Free
Topic: Electrostatics·Practice all Electrostatics questions

More Electrostatics Questions

Three capacitors C1, C2 and C3 are connected as shown in the figure to a battery of V volt. If the capacitor C3 breaks d...An electron falls from rest through a vertical distance h in a uniform and vertically upward directed electric field E. ...Charges Q, 2Q and 4Q are uniformly distributed in three dielectric solid spheres 1, 2 and 3 of radii R/2, R and 2R respe...A point charge q of mass m is located at the centre of a ring having radius R and charge Q. When it is displaced slightl...A charged water drop of radii 0.1 mm is under equilibrium in some electric field. The charge on the drop is equivalent t...