Question

Two compass needles are placed near a current carrying wire at points P and Q as shown in the figure. What can be concluded?

• A. Their needles will not deflect.
• B. Needle at P only will deflect
• C. Both the needles will deflect in the same direction.
• D. The needles will deflect in opposite directions

Answer 1

The correct option is D The needles will deflect in opposite directions

Magnetic field due to wire is circular with wire passing through the center of circle. In above fig field line will be coming out of page at point P and going into the page at point Q So needle at P will point toward you (i.e. out of page) and at Q it will point into the page. Therefore (d) is the correct option.