A line passing through places having zero value of magnetic dip is called

The lines of forces due to earth's horizontal component of magnetic field are

Assertion : The true geographic north direction is found by using a compass needle.

Reason : The magnetic meridian of the earth is along the axis of rotation of the earth.

The angle of dip at a place is $40.6°$ and the intensity of the vertical component of the earth's magnetic field $V = 6 \times {10^{ - 5}}$ $Tesla$. The total intensity of the earth's magnetic field $ (I) $ at this place is

A bar magnet is situated on a table along east-west direction in the magnetic field of earth. The number of neutral points, where the magnetic field is zero, are

If $\theta _1$ and $\theta_2$ be the apparent angles of dip observed in two vertical planes at right angles to each other, then the true angle of dip $\theta$ is given by