State with reason what will be the nature of polarity at the top of a vertical iron rod grounded partially at a place in the southern hemisphere of earth.

At any place the horizontal component of earth is sqrt3 times the vertical one. What is the angle of dip at that place?—

What is the angel of dip at a place where the horizontal and vertical components of the Earth's magnetic field are equal?

A vertical iron pillar is magnetised in a few years if it is partially pit underground. In the northern hemisphere, what would be the polarity at its top?

In vacuum, equal charges of the same nature are placed at the vertices of an equilateral triangle. What will be the electric field intensity and potential at the centroid of the triangle?

A wire is kept horizontally at a place in the northern hemisphere of the earth . In what direction will force act on the wire due to the vertical component of the earth's magnetic field , if electric current flows through the wire from south to north ?

On a smooth plane inclined at 30^(@) with the horizontal, a thin current carrying metallic rod is placed parallel to the horizontal ground. The plane is in a uniform magnetic field of 0.15T alon the vertical direction. For what value of current can the rod remain stationary ? the mass per unit lenght of the rod is 0.30 kg/m.