A long wire \( A B \) is placed on a table. Another wire \( P Q \) ...

A long wire \( A B \) is placed on a table. Another wire \( P Q \) of mass \( 1.0 \mathrm{~g} \) and length \( 50 \mathrm{~cm} \) is set to slide on two rails \( P S \) and \( Q R \). A current of \( 50 \mathrm{~A} \) is passed through the wires. At what distance above \( A B \), will the wire \( P Q \) be in equilibrium
(a) \( 25 \mathrm{~mm} \)
(b) \( 50 \mathrm{~mm} \)
(c) \( 75 \mathrm{~mm} \)
(d) \( 100 \mathrm{~mm} \)