The National 5 Physics exam is made up of two question papers. Paper 1 is a multiple choice paper. Paper 2 is made up of questions with several parts that need written answers.
Showing clear working not only enhances the chances of a correct answer but allows the marker to give credit for good understanding and some marks for an ultimately incorrect answer.
Give answers to an appropriate number of significant figures. Putting the wrong number of significant figures in an answer can carry a penalty that will reduce your final mark.
Finally, always check units - have you converted any units (e.g. kΩ to ohms for
resistance) and have you given units for answers where appropriate?