Physics
stars which appear single to the naked eye but are double when seen through a telescope are

asteroids
novas and supernovas
binaries
quasars

ANSWER DOWNLOAD EXAMIANS APP

Physics
Radiocarbon is produced in the atmosphere as a result of

Action of ultraviolet light from the sun on atmospheric oxygen.
Action of solar radiations particularly cosmic rays on carbon dioxide present in the atmosphere.
Lightning discharge in atmosphere.
Collision between fast neutrons and nitrogen nuclei present in the atmosphere.

ANSWER DOWNLOAD EXAMIANS APP