A dip circle is adjusted so that its needle moves freely in the magnetic meridian. In this position, the angle of dip is $40°$. Now the dip circle is rotated so that the plane in which the needle moves makes an angle of $30°$ with the magnetic meridian. In this position the needle will dip by an angle

A current carrying coil is placed with its axis perpendicular to $N-S$ direction. Let horizontal component of earth's magnetic field be $H_0$ and magnetic field inside the loop be $H$. If a magnet is suspended inside the loop, it makes angle $\theta $ with $H$. Then $\theta =$

The value of the horizontal component of the earth's magnetic field and angle of dip are $1.8 \times {10^{ - 5}}\,Weber/{m^2}$ and $30°$  respectively at some place. The total intensity of earth's magnetic field at that place will be

If the angles of dip at two places are $30^o$ and $45^o$ respectively, then the ratio of horizontal components of earth's magnetic field at the two places will be

At a certain place the horizontal component of the earth’s magnetic field is $B_0$ and the angle of dip is $45^o$. The total intensity of the field at that place will be

What are the Earth magnetic elements defined ? And which are they ?