The third great defect of our civilization is that it does not know what to do with its knowledge. Science has given us powers fit for the gods, yet we use them like mall children. For example, we do not know how to manage our machines. Machines were made to be man's servants; yet he has grown to dependent on them that they are in a fair way to become his masters. Already most men spend most of their lives looking after and waiting upon machines. And the machines are very stern masters. They must be fed with coal, and gives petrol to drink, and oil to wash with, and they must be kept at the right temperature. And if they do not get their meals when they expect them, they grow sulky and refuse to work, or burst with rage, and blow up, and spread rain and destruction all round them. So we have to wait upon them very attentively and do all that we can to keep them in a good temper. Already we find it difficult either to work or play without the machines, and the time may come when they will rule us altogether, just as we rule the animals.

Which of the following adjectives have been used in the passage to explain the temperamental nature of machines?

Stern

The correct answer is Option (3) → Stern

The word "stern" is used to describe the nature of machines. When we say that machines are "stern masters," it implies that they are strict, severe, or harsh in their behavior. This suggests that machines demand precise conditions for operation and can react negatively if those conditions are not met, as mentioned in the passage where they "grow sulky and refuse to work, or burst with rage, and blow up." Therefore, "stern" is used here to illustrate how machines can exhibit characteristics similar to those of a strict or demanding master, which emphasizes their temperamental nature.