How is strong pressure gradient represented on a weather map?

The correct answer is A, Closely spaced isobars. Isobars are lines on a weather map joining places that have the same atmospheric pressure, reduced to sea level. The pressure gradient is the rate at which pressure changes over a horizontal distance. When isobars are drawn at a fixed interval, say every 2 or 4 millibars, closely spaced lines mean pressure changes sharply over a short distance, so the gradient is steep; the pressure gradient force is then strong and winds blow fast, as around a tropical cyclone. Option B is wrong because widely spaced isobars show a weak gradient and light winds. Option C is wrong because the gradient is shown wherever the lines are close, not only at the edge of a pressure system. Option D is wrong because such a pattern shows a gradient that changes from weak to strong, not a strong gradient as such. Exam tip: close isobars = steep gradient = strong winds; wide isobars = gentle gradient = calm weather.