Question

When a magnetic compass needle is carried nearby to a straight wire carrying current, then
(I) the straight wire cause a noticeable deflection in the compass needle.
(II) the alignment of the needle is tangential to an imaginary circle with straight wire as its centre and has a plane perpendicular to the wire

• A. (I) is correct
• B. (II) is correct
• C. Both (I) and (II) are correct
• D. Neither (I) nor (II) correct

Answer 1

The correct option is C Both (I) and (II) are correct

When magnetic needle kept in the magnetic field produce by the straight wire, The needle get deflected and it will reach in equilibrium petition in which direction & magnetic field and magnetic moment of the needle direct in same direction.

In case Magnetic field produce by the straight wire is circular, direction of Magnetic needle show the temgent of circle of magnetic field.

Hence, Both statement is correct.