Two identical magnetic dipoles of magnetic moments $1.0 \,A-m^2$ each, placed at a separation of $2\,m$  with their axis perpendicular to each other. The resultant magnetic field at a point midway between the dipoles is

In the case of bar magnet, lines of magnetic induction

If a magnet of pole strength $m$  is divided into four parts such that the length and width of each part is half that of initial one, then the pole strength of each part will be

A vibration magnetometer consists of two identical bar magnets placed one over the other such that they are perpendicular and bisect each other. The time period of oscillation in a horizontal magnetic field is ${2^{5/4}}$ $seconds$. One of the magnets is removed and if the other magnet oscillates in the same field, then the time period in seconds is

The magnetic field to a small magnetic dipole of magnetic moment $M$, at distance $ r$  from the centre on the equatorial line is given by (in $M.K.S. $ system)