S. KusamranA. SrongprapaT. PruttivarasinP. KittaraW. PrachyabruedS. PratontepP. TrivejChulalongkorn UniversityKing Mongkut's Institute of Technology LadkrabangMahidol UniversitySouth Carolina Commission on Higher EducationKasetsart University2018-06-112018-06-112012-11-01European Journal of Physics. Vol.33, No.6 (2012)13616404014308072-s2.0-84867715731https://repository.li.mahidol.ac.th/handle/20.500.14594/15188This paper presents both the theoretical (without solutions) and the experimental problems for the 42nd International Physics Olympiad (IPhO42) organized in Bangkok, Thailand, 1018 July 2012. Experimental problems on electrical and mechanical black boxes are given with detailed solutions. The performance of the contestants in the theoretical and the experimental sections is compared. © 2012 IOP Publishing Ltd.Mahidol UniversityPhysics and AstronomyArticleSCOPUS10.1088/0143-0807/33/6/S1