Geography

The areas around the North and South poles within the Polar circles are known as the Frigid Zone because they experience extremely cold temperatures year-round.

The largest latitude circle on Earth is the Equator, which divides the Earth into the Northern and Southern Hemispheres and has the greatest circumference of all latitude lines.

Orographic rainfall occurs when moist air is forced to rise over mountains, cooling and condensing to form rain. This is distinct from other types such as monsoon or cyclonic rainfall.

The areas around the North and South poles within the Polar circles are known as the Frigid Zone because they experience extremely cold temperatures year-round.

Frost shattering, also known as freeze-thaw weathering, occurs on valley sides above glaciers where water enters cracks, freezes, expands, and breaks the rock apart. This process is typical above the glacier surface, unlike plucking and abrasion which occur at the glacier base, and chemical weathering which is less dominant in cold environments.

The Sukkur Barrage on the Indus River near Sukkur, Pakistan, was constructed during the British Raj from 1923 to 1932. It was completed and officially opened in 1932. Therefore, the correct answer is 1932 (option A). The date 1928 (option D) is incorrect as the barrage was not completed or operational at that time.

A wind that reverses its direction seasonally is called a monsoon. Monsoons are characterized by a seasonal reversal in wind direction, typically bringing wet and dry seasons.

The Gulf Stream is primarily caused by the large-scale circulation of the North Atlantic Subtropical Gyre, which is driven by prevailing winds (trade winds and westerlies) and Earth's rotation (Coriolis effect). This wind-driven gyre causes water to pile up along the western edge of the Atlantic Ocean, creating a difference in water level (sea surface height) that drives a strong, narrow, and fast current known as the Gulf Stream. This difference in water level, combined with density differences due to temperature and salinity, creates pressure gradients that sustain the Gulf Stream. Therefore, among the given options, 'Difference in water level' best explains the cause of the Gulf Stream.

The largest latitude circle on Earth is the Equator because it is the circle that divides the Earth into the Northern and Southern Hemispheres and has the greatest circumference compared to other latitude lines.

Each degree of longitude corresponds to a 4-minute difference in time because the Earth rotates 360 degrees in 24 hours, so 1 degree equals 4 minutes (24 hours × 60 minutes ÷ 360 degrees = 4 minutes per degree).