Q. Given below are two statements, one is labelled as Assertion (A) and the other as Reason (R).
Assertion (A): Jet streams discovered during World War II are high altitude easterly winds.
Reason (R): Jet streams flow with a speed of 300 – 500 km/hour.
Select the correct answer from the codes given below.
a) Both (A) and (R) are true and (R) is the correct explanation of (A).
b) (A) is false, but (R) is true.
c) Both (A) and (R) are true, but (R) is not the correct explanation of (A).
d) (A) is true, but (R) is false.
Question from UPPSC Prelims 2024
Correct Answer: b) (A) is false, but (R) is true.
Explanation:
– Assertion (A): Jet streams are not high-altitude easterly winds; they are high-altitude westerly winds. Jet streams flow from west to east in the upper atmosphere, typically in the tropopause region. Therefore, the assertion is false.
– Reason (R): Jet streams indeed flow with very high speeds, ranging from 300 to 500 km/hour. This statement is true.
There are several different jet streams, or jets, around the globe. The polar jet is located between the 50°-60° latitude lines in both the northern and southern hemispheres. The subtropical jet is located around the 30° latitude line. Jet streams vary in height of four to eight miles and can reach speeds of more than 275 mph (239 kts / 442 km/h).
Since the assertion is false but the reason is true, the correct answer is b) (A) is false, but (R) is true.
