Identical compasses are placed at three locations: Point A on the geographic equator…
PHYSICS · Single correct · CBSE · Physics · Electricity: Magnetic and Heating Effects · Electricity: Magnetic and Heating Effects
Problem
Identical compasses are placed at three locations: Point A on the geographic equator (0mo), Point B at 45mo N, and Point C at 80mo N. Neglecting local anomalies, at which point is the horizontal component of Earth’s magnetic field the greatest?
(a) Point B, because when the dip angle is 45∘ the horizontal and vertical components are equal, giving the greatest possible horizontal component.
(b) Point C, because the total field strength is largest near the poles.
(c) Point A, because the field lines are nearly horizontal at the equator.
(d) Point C, because the horizontal component is proportional to sin(dip), which is largest near the poles.