Question

Magnetic field of earth is identical to magnetic field of a giant magnet held ${20}^o$ west of geographic $N-S$ at the centre of earth. At equator, horizontal component of earth is $0.32G$ . Vertical component can be calculated from the relation $V=H\tan \delta$, where $\delta$ is angle of dip at the place. The value of $\delta =0^o$ at equator and $\delta ={90}^o$ at poles. What is the order of magnetic declination at a place on earth :

• A. ${20}^o$ East
• B. ${10}^o$ East
• C. ${20}^o$ West
• D. ${10}^o$ West

Answer 1

The correct option is C ${20}^o$ West

Magnetic declination or variation is the angle on the horizontal plane between magnetic north (the direction the north end of a compass needle points, corresponding to the direction of the Earth's magnetic field lines) and true north (the direction along a meridian towards the geographic North Pole). Here, the order of magnetic declination at a place on earth is ${20}^{\circ }$ west as a giant magnet held ${20}^{\circ }$ west of geographic N-S at the center of earth.