The declination at a place is `12^@C` west of north. Find in what direction, a ship should stear so that it reaches a place due east?

A ship is sailing due east according to Mariner's compass. If the declination of that plae is 18^@C east of north, what is the true directio of the ship?

A magnetic needle free to rotate about the vertical direction (compass ) point 3.5 west of the geographic north . Another magnetic needle free to rotate in a vertical plane parallel to the magnetic meridian has its north tip pointing down at 18^(@) with the horizontal . The magnitude of the horizontal component of the earth ' magnetic field at the place is known to be 0.40 G . what is the direction and magnitude of the earth's magnetic field at the place ?

At a certain location in Africa, a compass points 12^@ west of the geographic north. The north tip of the magnetic needle of a dip circle placed in the plane of magnetic meridian points 60^@ above the horizontal. The horizontal component of the earth’s field is measured to be 0.16 G. Specify the direction and magnitude of the earth’s field at the location.

A telephone cable at a place has four long straight horizontal wires carrying a current of 1.0 A in the same direction east to west. The earth’s magnetic field at the place is 0.39 G, and the angle of dip is 35^@ . The magnetic declination is nearly zero. What are the resultant magnetic fields at points 4.0 cm below and above the cable?

Force of attractio between two point electric charges placed at a distance .d. in a medium is F. What distance apart should these be kept in the same medium, so that between them beComes F//3

A long straight horizontal cable carries a current of 2.5 A in the direction 10^@ south of west to 10^@ north of east. The magnetic meridian of the place happens to be 10^@ west of the geographic meridian. The earth’s magnetic field at the location is 0.33 G, and the angle of dip is zero. Locate the line of neutral points (ignore the thickness of the cable)? (At neutral points, magnetic field due to a current-carrying cable is equal and opposite to the horizontal component of earth’s magnetic field.)