JEE Main 2025 Physics question

An air bubble of radius 0.1 cm lies at a depth of 20 cm below the free surface of a liquid of density 1000 kg/m³. If the pressure inside the bubble is 2100 N/m² greater than the atmospheric pressure, then the surface tension of the liquid in SI unit is (use g = 10 m/s²)

• (1)0.02
• (2)0.1
• (3)0.25
• (4)0.05Correct