Questions

Radioactive decay is likely to occur when the nuclei of an atom doesn't have enough binding energy to hold the nucleus together due to excess of rotons or nutrons in it.

New York City, London, and Tokyo are the richest cities in the world 2018, according to their ranks.

When you compress or stretch a spring, as soon as the stress is relieved, the spring attains its normal shape instantly. Its Elastic potential energy helps it do so. Generally, these elastic substances follow the Hooke’s law.

According to this Law, the force needed to change the shape of spring is proportional to the displacement of the spring. The displacement referred here is how far the spring is compressed or stretched from its normal shape. Mathematically, Hook’s Law can be summarised as F= – k x. Here ‘k’ is the spring constant and ‘x’ is the displacement.

The upper house of the parliament is the Rajya Sabha and is a permanent body.

Goitre is characterized by the swelling of the neck region. This is due to the enlargement of the thyroid gland which secretes hormone thyroxine. Thyroxine has iodine as an integral part of it. If there is not sufficient iodine in one's  diet, the thyroid gland swells up.