What is the ruling regarding the salary of an engineer whose work does not exceed 10% of his working hours, and is it permissible for him to carry out personal tasks on his private computer during his free time?

An employee, whether working overtime or regular hours, is considered a private employee. If he presents himself for work, and the employer or an authorized person grants him permission to leave, he is entitled to his wages, even if there is no work available. It is permissible for the employee to use his personal computer during his free time, provided it does not affect his work. However, it is preferable to obtain permission from the employer.