A thin wire of length 'L' is bent into a planar loop of irregular shape. A current 'I' flows through it. The loop is placed in a uniform magnetic field 'B' with its plane perpendicular to the field. If the magnetic moment of a circular loop of same perimeter and carrying same current is $\mu_c$, the magnetic moment ($\mu$) of the irregular loop satisfies:

A current carrying loop has a magnetic moment 'M'. If the current is doubled and the area of the loop is halved, what will be the new magnetic moment?

If two identical bar magnets, each of length $l,$ pole strength $m$ and magnet moment $M,$ are placed perpendicular to each other with their unlike poles in contact, the magnetic moment of the combination is

Three identical bar magnets each of magnetic moment $M$ are arranged in the form of an equilateral triangle such that at two vertices like poles are in contact. The resultant magnetic moment will be

A long thin magnet of moment $M$ is bent into a semicircle. The decrease in the magnetic moment is

Two identical bar magnets are placed one above the other such that they are mutually perpendicular and bisect each other. The time period of this combination in a horizontal magnetic field is $T$. The time period of each magnet in the same field is

A thin wire of length 'L' is bent into a planar loop of irregular shape. A current 'I' flows through it. The loop is placed in a uniform magnetic field 'B' with its plane perpendicular to the field. If the magnetic moment of a circular loop of same perimeter and carrying same current is $\mu_c$, the magnetic moment ($\mu$) of the irregular loop satisfies:

A bar magnet is cut into two equal halves along its length. The magnetic moment of each half will be:

Two short magnets $AB$ and $CD$ are in the $X - Y$ plane and are parallel to $X$-axis and co-ordinates of their centers respectively are (0, 2) and (2, 0). Line joining the north-south poles of $CD$ is opposite to that of $AB$ and lies along the positive $X$-axis. The resultant field induction due to $AB$ and $CD$ at a point $P$ (2, 2) is $100 imes {10^{ - 7}}{\rm{\;T}}$. When the poles of the magnet $CD$ are reversed, the resultant field induction is $50 imes {10^{ - 7}}{\rm{\;T}}.$ The value of magnetic moments of $AB$ and $CD$ (in ${\rm{A}}{{\rm{m}}^2}$) are

Two identical magnetic dipoles of magnetic moment 'm' are placed at a distance 'd' apart with their axes perpendicular to each other. The resultant magnetic moment of the combination is:

A steel wire of length $l$ has a magnetic moment $M.$ It is bent at its middle point at an angle of 60$^ \circ$. Then the magnetic moment of new shape of wire will be