In a resonance column first and second resonance are obtained at depths 22 . 7 cm and 70 . 2 cm . The third resonance will be obtained at a depth

Step-by-step solution

l 1 + x = 22.7   +   x = λ 4 l 2 + x = 70.2   +   x = 3 λ 4 l 3 + x = 5 λ 4 x = l 2 - 3 l 1 2 = 70.2 - 68.1 2 = 2.1 2 = 1.05   c m l 3 + x l 1 + x = 5 l 3 = 5 l 1 + 4 x = 5 × 22.7 + 4 × 1.05 = 117.7   c m