A dip needle with a circular scale is mounted on a horizontal axis. How can the direction of the magnetic meridian be found with the help of this needle?

In the diagram below is shown a circular loop carrying current I. show that the direction of magnetic field with the help of lines of force.

The figure TBQ 9.38 shows an equiconvex lens (of refractive index 1.50) in contact with a liquid layer on top of a plane mirror. A small needle with its tip on the principal axis is moved along the axis until its inverted images if found at the positions of hte needle. The distance of the needle from the lens is measured to be 45.0 cm. The new distane is measured to be 30.0 cm. What is the refractive index of the liquid?

An equiconvex lens with radii of curvature of magnitude R each,is put over a liquid layer poured on top of a plane mirror.A small needle ,with its tip on the principal axis of the lens,is moved along the axis until its inverted real image coincides with the needle itself.The distance of the needle from the lens is measured to be a as shown in Fig.2.53. On removing the liquid layer and repeating the ezperiment,the distance is found to be b as shown in Fig.254 .Gien that tow values of distances meeawured reepresent the focal length values in the two cases, obtain a formula for the refractive index of the liquid. .

A short bar magnet is placed in a horizontal plane with its axis in the magnetic merdian . Null points are found on its equitorial line (i.e., its normal bisector) at 12.5 cm and the earth's magnetic field at the place is 0.38 G the angle of dip is zero. (i) What is the total magnetic field at points on the axis of the magnet located by the same distance (12.5 cm) as the null-points from the centre? (ii) Locate the null points when the magnet is turned around by 180^(@) . Assume that the length of the magnet is negligible as compared to the distance of the null-point from the centre of the magnet.

A dip circle is adjusted so that its needle moves freely in the magnetic meridian. In this position, the angle of dip ia 45^(@) . 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

How can the angle of dip be determined without placing the dip circle in the plane of magnetic meridian?

Looking at a ciruclar coil, the current found to be flowing in anticlockwise diretion. Predict the direction of magnetic field produced at a point on the axis of the coil on the same side as the observer