Question

A student uses a magnetic compass to perform a laboratory experiment in the Northern Hemisphere. She then carries the same magnetic compass with her to the Southern Hemisphere, taking care not to damage the compass in any way. When she reaches her destination at the equivalent latitude and longitude in the Southern Hemisphere, she prepares to perform the same laboratory experiment. The student looks at the compass before performing the experiment to see if the compass needle has changed. How has the compass changed?
A. The compass needle points $90^{\circ}$ to the left of the expected direction
B. The compass needle points $90^{\circ}$ to the right of the expected direction
C. The compass needle slowly rotates in a counter-clockwise direction
D. The compass needle slowly rotates in a clockwise direction
E. There has been no change in the compass

Answer 1

Recall the basics of the magnetic compass needle like what is a compass needle, in which direction does the needle of the magnetic compass point or it has effect on any atmospheric conditions or geographic positions on its direction. Using this information, check what will be the change in the direction of the needle when the girl moves from Northern Hemisphere to Southern Hemisphere.

Complete step by step solution:
The magnetic compass needle is an instrument consisting of a magnetized needle used to determine the directions at an unknown place.
The property of the magnetic needle is that it always points in the geographic North Pole of the Earth.
Hence, whether the girl is in the Northern Hemisphere or Southern Hemisphere, the needle of the magnetic compass will always point towards the geographic North Pole of the Earth.
Therefore, there will not be any change in the compass.

So, the correct answer is “Option E”.

Additional Information:
The Earth is like a big magnet with its magnetic south pole lying near the geographic North Pole and magnetic north pole lying near geographic South Pole.
The needle in the compass is magnetized. Hence, when it is held freely, it always points towards the geographic North Pole of the Earth which is the magnetic south pole of the Earth

Note:
The Northern Hemisphere and Southern Hemisphere of the Earth are the positions of the Earth lying from the North Pole to the equator and South Pole to the equator respectively. The students should get confused by considering that the Northern Hemisphere and Southern Hemisphere of the Earth are geographic South and North half portions of the Earth like geographic and magnetic North-South poles of the Earth.