A line passing through places having zero value of magnetic dip is called
Isoclinic line
Agonic line
Isogonic line
Aclinic line
The angle of dip is the angle
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
A dip needle in a plane perpendicular to magnetic meridian will remain
The lines of forces due to earth's horizontal component of magnetic field are
A compass needle will show which one of the following directions at the earth's magnetic pole