EXTRACTED_TEXT: open Organ Pipe : Standing wave form in sound A N A l = λ/2 λ = 2l f = V/λ = V/2l fundamental or wire at fixed end A N A N A λ' = l f' = V/l nᵗʰ harmonic f = nV / 2l No of Node = n No of Antinode = n+1 n = 1, 2, 3, 4, ... ... first harmonic 3rd harmonic second harmonic or first overtone MAIN_QUESTION: There is no explicit question being asked. The image serves as an explanatory slide detailing concepts related to standing waves in an open organ pipe, including definitions, formulas for frequency and harmonics, and node/antinode counts. KEY_INFORMATION: * **Topic:** Open Organ Pipe and Standing Waves. * **Fundamental mode in open organ pipe:** length l = λ/2, wavelength λ = 2l, fundamental frequency f = V/λ = V/2l. * **General formula for nᵗʰ harmonic (open organ pipe):** f = nV / 2l * **Number of Nodes for nᵗʰ harmonic:** No of Node = n * **Number of Antinodes for nᵗʰ harmonic:** No of Antinode = n+1 * **Harmonic series:** * n = 1: first harmonic * n = 2: second harmonic or first overtone * n = 3: 3rd harmonic * n = 4: ... (and so on) * **Alternative case (or wire at fixed end):** For λ' = l, frequency f' = V/l. * **Labels in diagrams:** A (Antinode), N (Node). * **Symbols:** f (frequency), V (wave speed), λ (wavelength), l (length), n (harmonic number).