Indeed -but what I meant was that (in my opinion) it makes that type of exam even 'worse'.Well, yes but not with regard to the exam in question.
Sure, there obviously is no universally correct (numerical) answer. However, that doesn't alter the fact that to be competent in practice, a person needs to have enough understanding, intelligence and common sense to be able to make a (inevitably 'numerical') reasonable decision as to how deeply to bury the cable in any particular situation they encounter.I suppose there is no depth that would cover all situations - "shall be at a sufficient depth to avoid being damaged by any reasonably foreseeable disturbance of the ground" ... is what it states.
Kind Regards, John