question_answer

A copper wire is wound on a wooden frame, whose shape is that of an equilateral triangle. If the linear dimension of each side of the frame is increased by a factor of 3 keeping the number of turns of the coil per unit length of the frame the same then the self-inductance of the coil [JEE  Main Online Paper (Held on 11-jan-2019 Evening)]

A) increases by a factor of 27

B) decreases by a factor of \[9\sqrt{3}\]

C) increases by a factor of 3

D) decreases by a factor of 9