A current of 2A flows through 5 turn coil of a tangent galvanometer having a radius of 12.5 cm. If the deflection of the needle at the centre is 450, the horizontal component of the earth field at the point is
16`pi` `xx` 10-5T
16`pi` `xx` 10-6T
16`pi` `xx` 10-7T
16`pi` `xx` 10-8T