Questions

Panacea, also known as panchrest, is a medicine supposed remedy that is claimed to cure all diseases and prolong life indefinitely. It is named after the Greek goddess of universal remedy Panakeia.

For undo the action or last action [Ctrl + Z] is used.

This orbital velocity at the moon is less because orbital velocity = rg

where 'r ' is the orbital radius. i.e the distance of the body from the center of the earth and 'g' is the acceleration due to gravity on the body in question. In the case of the moon, both r and g are less than in the case of the earth.

Before transferring the fish, the position is the man with the fish and the bucket of water. After transferring the position is: the man without the fish, but the fish inside the water in the bucket. Thus to know  whether there is any change in weight, it is enough to consider whether there is any change in weight when the fish in air is transferred into the water. The answer is there is no change as when in water though it loses weight due to upthrust of water on it, the level of water increases and exerts an equal force at the bottom.So, (c) is correct.

In 1985 the physicist Wilhelm Rontgen discovered X-rays, the "X" signifying their unknown origin.He later found that the rays could pass through flesh and by using photographic plates could make images of bones inside the body. 

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.

Silver chloride is a chemical compound with the chemical formula AgCl is also called as Horn Silver. It is also called as cerargyrite. It is a gray, very heavy halide mineral and an ore of silver.