The Construction and Validation of Physics Test Measuring Students' Concept Understanding on Fluid

Student's understanding of Physics plays a vital role for Vocational students especially in the aviation program. This urgency, a strong basic science, also written in SKKNI of aviation. One of Physics topic that has a close relation with aviation is fluid, for both static and dynamic fluid. This research aims for developing an instrument as well as knowing student's concept understanding about fluid. The instruments were developed through content validity and tested to 105 students grade XI of SMK Penerbangan Bina Dhirgantara. The data were analyzed using quest program and student's concept understanding were described by looking at student's responses at each number. The result shows that from 25 questions tested, 21 questions are qualified and 4 questions were rejected. The most difficult questions for students are determining factors affecting the magnitude of hydrostatic pressure, explaining how the pascal's law works in the hydraulic system of an airplane and applying the concept of Bernoulli's law in the combustion chamber.