ElectrostaticsHard

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

The work done in rotating an electric dipole of dipole moment p in an electric field E through an angle θ from the ...Two identical thin rings, each of radius R meter are coaxially placed at distance R meter apart. If Q1 and Q2 coulomb ar...When an electric dipole is kept in a uniform electric field then for what value of the angle between and,torque will be ...A system consisting of two charges 7μC and -2μC placed at (-9 cm, 0, 0) and (9 cm, 0, 0) respectively. This sy...Two charges 16μC and - 4μC are placed at seperation 27 cm, then distance of the point from - 4 μC where e...