Question

Which of the following statement is (are) correct in the given figure ?

• A. Net force on the loop is zero
• B. Net torque on the loop is zero
• C. Loop will rotate clockwise about axis OO' when seen from O
• D. Loop will rotate anticlockwise about OO' when seen from O

Answer 1

Answer: (C)

Loop will rotate clockwise about axis OO' when seen from O

Answer 2

$F_{BA}$ , =0, because magnetic lines are parallel to this wire. $F_{CD}> 0$, because magnetic lines are antiparallel to this wire.

$F_{CB}$ is perpendicular to paper outwards and $F_{AD}$ is perpendicular to paper inwards. These two forces (although calculated by integration) cancel each other but produce a torque which tend to rotate the loop in clockwise direction about an axis OO'