We should always write In good handwriting in exams not only in exams even in notebooks also. Some school give marks of notebook also. 1 mark is for cover of nb, 1 mark is for handwriting of yours, 2 marks is for completing your nb and 1 mark is for giving nb in time. So total marks of nb are 5 marks. If in exams you will not write in good handwriting then teacher will not able to read. So she will give you less marks. When your marks are less then some teachers see your handwriting and give 1 or 2 marks extra. If you will write in good handwriting there are many advantages . So you should always write in good handwriting only.