Practice question

Given: A tank of water (refractive index = 1.33) has a depth of 20 cm . What is the apparent depth when viewed normally? These values define the system as per NCERT data. Formula: Apparent depth = fracreal depthn. This is the standard NCERT relation for this phenomenon. Substitution & Calculation: Real depth = 20 cm, n = 1.33 . Apparent depth = 20/1.33 approx 15.04 cm . Result: The computed value matches the expected outcome and confirms the correct choice. Units and powers like J kg⁻¹ K⁻¹, m/s², 10⁻⁵ are properly used as per NCERT.