NEET2008PhysicsElectrostaticsActual
A thin conducting ring of radius R is given a charge +Q . The electric field at the centre O of the ring due to the charge on the part A K B of the ring is E . The electric field at the centre due to the charge on the part A C D B of the ring is
Options
- A3 E along KO
- BE along O K
- CE along K O
- D3 E along O K
Correct answer
B. E along O K
Step-by-step solution
Key Idea: It is given that the ring is conducting. As the ring is conducting, so electric field at its centre is zero, ie, E _ total =0 aligned E _ A K B + E _ A C D B & =0 E _ A C D B & =- E _ A K B E _ A C D B & =- E (along K O ) aligned Therefore, the electric field at the centre due to the charge on the part A C D B of the ring is E along O K . lternative : The fields at O due to A C and B D cancel each other. The field due to C D is acting in the direction O K and equal in magnitude to E due to A K B .