Question

Two straight long conductors AOB and COD are perpendicular to each other and carry currents I₁ and I₂ . The magnitude of the mag. field at a point 'P' at a distance 'a' from the point 'O' in a direction perpendicular to the plane ABCD is

Options:
(a) `mu_0/(2pia)(I_1+I_2)` (b) `mu_0/(2pia)(I_1-I_2)` (c) `mu_0/(2pia)(I_1^2+I_2^2)^(1/2)` (d) `mu_0/(2pia)(I_1I_2)/(I_1+I_2)`