1.
A long straight wire carrying a current of 30 A30\,\text{A} is placed in an external uniform magnetic field of induction 4×10−4 T4 \times 10^{-4}\,\text{T}. The magnetic field is acting parallel to the direction of current. The magnitude of the resultant magnetic induction in tesla at a point 2.0 cm2.0\,\text{cm} away from the wire is (μ0=4π×10−7 H/m\mu_0 = 4\pi \times 10^{-7}\,\text{H/m})