By signing in you confirm you are 18 or older, or have your parent’s or guardian’s consent.

NDA 1 2025 GAT, question 91

Topic: Geography

Q91

Which of the following statements with reference to Coriolis force is/are correct ?

  1. Coriolis force acts perpendicular to the pressure gradient force

  2. At the equator, the Coriolis force is zero and the wind blows perpendicular to the isobars

Select the answer using the code given below :

  1. (a) 1 only
  2. (b) 2 only
  3. (c) Both 1 and 2Correct answer
  4. (d) Neither 1 nor 2

Solution.

Answer: (c) Both 1 and 2

  1. Statement 1: in the school geography account, the Coriolis force acts at right angles to the pressure gradient force and deflects the wind.
  2. Statement 2: the Coriolis force is zero at the equator, so the wind blows straight across (perpendicular to) the isobars.

Trap: Strictly, the Coriolis force acts at right angles to the wind's direction of motion; statement 1 is the simplified textbook version, which UPSC follows.