Given below are two statements: Statement I: When a straight bar magnet of magnetic moment M is bent into a semicircle, its magnetic moment decreases to 2M . Statement II: The pole strength of a bar magnet decreases when it is bent into a curved shape. In the light of the above statements, choose the most appropriate answer from the options given below:

Step-by-step solution

Statement I is correct: Let the initial length of the bar magnet be L and its pole strength be m . Its magnetic moment is M = mL . When bent into a semicircle of radius R , the arc length is L = R , which gives R = L . The new effective magnetic length is the shortest distance between the poles, which is the diameter 2R = 2L . The new magnetic moment is M' = m ( 2L ) = 2M . Statement II is incorrect: The pole strength of a bar magnet depends only on the nature of the material and its cross-sectional area. It does n