A thin conducting ring of radius `R` is given a charge `+Q`, Fig. The electric field at the center `O` of the ring due to the charge on the part `AKB` of the ring is `E`. The electric field at the center due to the charge on part `ACDB` of the ring is

Options

A. `E` along `KO`
B. `3E` along `OK`
C. `3E` along `KO`
D. `E` along `OK`

Answer

4

Explanation

Electric field at `O` is zero. Electric field at `O` due to `ACDB` is equal and opposite to electric field at `O` due to `A K B` ,i.e. `E` along `OK`.