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 :

The Coriolis force is a deflective force caused by the Earth's rotation. Statement 1 is correct because the Coriolis force acts perpendicular to the pressure gradient force [1]. While the pressure gradient force is perpendicular to isobars, the Coriolis force acts perpendicular to the wind direction, eventually balancing the pressure gradient force in geostrophic conditions [2]. Statement 2 is also correct. The magnitude of the Coriolis force is determined by the formula 2vω sin ϕ, where ϕ is the latitude [3]. At the equator (0° latitude), sin 0° is zero, making the Coriolis force absent [3]. Without the deflective Coriolis force to balance the pressure gradient, the wind cannot be deflected to blow parallel to isobars; instead, it blows directly from high to low pressure, perpendicular to the isobars [4]. This lack of deflection at the equator is why tropical cyclones do not form there.

Sources

1. [1] FUNDAMENTALS OF PHYSICAL GEOGRAPHY, Geography Class XI (NCERT 2025 ed.) > Chapter 9: Atmospheric Circulation and Weather Systems > Coriolis Force > p. 79
2. [2] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 27: Jet streams > Geostrophic Wind > p. 384
3. [3] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 23: Pressure Systems and Wind System > Causes of The Coriolis Effect > p. 309
4. [4] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 23: Pressure Systems and Wind System > Pressure Gradient Force > p. 306