A good exam questions should be able to gauge student’s understanding and achievement related to Course Outcome (CO), Bloom’s Taxonomy level and Programme Outcome (PO). To achieve this, a set of pre-test questions were prepared to evaluate the pre achievement level among the students related to CO, PO and the Bloom’s Taxonomy level. In this study, a pre-test for Differential Equations (KKKQ2123) was given to 100 second year students from the department of Electrical, Electronic and Systems Engineering. The level of Bloom’s Taxonomy measured consists of level 1 (knowledge) to level 6 (creation). Rasch Measurement Model was applied to analyse the reliability of the pre-test questions. The analysis revealed that all the pre-test questions were reliable and no questions were found unsuitable. Prior assessment (pre-test) is important in the preparation of final exam questions as it would indicate the level of student’s understanding in a particular topic that relates to the CO and PO of the programme.