172. The longest day (shortest night) in the southern hemisphere is

A. June 21
B. December 22
C. July 21
D. November 22
✅ The correct answer is option B.
In the Northern Hemisphere this is the shortest day of the year, which has the longest night and is called the Winter Solstice. For the northern hemisphere, the Winter solstice is around December 22. This means that the sun is at the southern tropic. For the southern Hemisphere, the winter solstice is around June 21.

175. The second largest island (next to Greenland) in the world is

A. Borneo
B. Malagasy
C. New Guinea
D. Sumatra
✅ The correct answer is option C.
New Guinea is the 2nd largest island in the world with an area of 303,500 sq mi (786,000 km sq), which is pretty significantly smaller than Greenland. The island actually houses two countries and is located in the middle of South East Asia.

176. The steady or initial phase of the magnetic storms is

A. preceded by storm sudden commencement
B. magnetic storm at middle and low altitudes
C. a sharp increase of the field
D. None of the above
✅ The correct answer is option A.
During these few minutes–the sudden-commencement phase–of the storm, the horizontal component of the geomagnetic field increases suddenly over the entire globe. The increase persists for two to six hours and is classified as the initial phase of the storm.

177. The length of the tropical years (the time interval between successive occurrences of the spring equinox) is decreasing very slowly as a result of

A. small, progressive changes in the earth’s rotational speed
B. small, progressive change in earth’s orbit around the sun
C. both (a) and (b)
D. None of the above
✅ The correct answer is option C.
both (a) and (b)