At a certain location in Africa, a compass needle points `15^@` west of the geogrphic north. What is the angle of declination at the point ?

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 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 ?

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 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.)

Consider the plane S formed by the dipole axis and the axis of earth. Let P be point on the magnetic equator and in S. Let Q be the point of intersecton of the geographically. Obtain the declination and dip angles at P and Q.

AB is a vertical pole with B at the ground level and A at the top. A man finds that the angle of elevation of the point A from a certain point C on the ground is 60^@ . He moves away from the pole along the line BC to a point D such that CD =7m. From D, the angle of elevation of the point A is 45^@ . Then the length of the pole is:

A tower stands vertically on the ground. Front a point on the ground. which is 15 m away from the foot of the tower, the angle of elevation of the top of the tower is found to be 60^@ . Find the height of the tower.

A compass needle free to turn in a horizontal plane is placed at the centre of circular coil of 30 turns and radius 12 cm. The coil is in a vertical plane making an angle of 45^@ with the magnetic meridian. When the current in the coil is 0.35 A, the needle points west to east. Determine the horizontal component of the earth’s magnetic field at the location.

A compass needle free to turn in a horizontal plane is placed at the centre of circular coil of 30 turns and radius 12 cm. The coil is in a vertical plane making an angle of 45^@ with the magnetic meridian. When the current in the coil is 0.35 A, the needle points west to east. The current in the coil is reversed, and the coil is rotated about its vertical axis by an angle of 90^@ in the anticlockwise sense looking from above. Predict the direction of the needle. Take the magnetic declination at the places to be zero.