A current of 10A is flowing from east to west in a long straight wire kept on a horizontal table. The magnetic field developed at a distance of 10 cm due north on the table is
Options:
(a) `2 xx10^(-5)T`, acting downwards
(b) `2 xx10^(-5)T`, acting upwards
(c) `4 xx10^(-5)T`, acting downwards
(d) 4 xx10^(-5)T`, acting upwards