At a certain place the angle of dip is $30°$ and the horizontal component of earth's magnetic field is $0.50$ Oersted. The earth's total magnetic field is
$\sqrt 3 $
$1$
$\frac{1}{{\sqrt 3 }}$
$\frac{1}{2}$
The line on the earth's surface joining the points where the field is horizontal is
A line passing through places having zero value of magnetic dip is called
Two short bar magnets of magnetic moments $m$ each are arranged at the opposite corners of a square of side $d$ such that their centres coincide with the corners and their axes are parallel. If the like poles are in the same direction, the magnetic induction at any of the other corners of the square is
A magnetic needle oscillates in a horizontal plane with a period $T$ at a place where the angle of dip is $60^{\circ}$. When the same needle is made to oscillate in a vertical plane coinciding with the magnetic meridian, its period will be
At a certain place, the horizontal component ${B_0}$ and the vertical component ${V_0}$ of the earth's magnetic field are equal in magnitude. The total intensity at the place will be