Questions

Processes that require or give off heat will be limited to changes of state, known as phase changes, and changes in chemical constitution, or chemical reactions. Changes of state involve a solid melting, a liquid freezing, a liquid boiling or a gas condensing.

An exothermic process is one that gives off heat, which is transferred to the surroundings. An endothermic process is a reaction which heat has to be supplied to the system from the surroundings.

Here in all the given options, heat is taken away from them to change there phase. 

Liquid to Solid --- Freezing

Gas to Liquid --- Condensation

Gas to Solid --- Deposition 

are all examples of exothermic processes.

Pitot tube is used to measure stagnation pressure.

At the center of the sun, nuclear fusion converts hydrogen into helium, energy, and neutrinos. Nuclear fusion is a reaction in which two or more atomic nuclei are combined to form one or more different atomic nuclei and subatomic particles (neutrons or protons).

In physics, the dynamo theory proposes a mechanism by which a celestial body such as Earth or a star generates a magnetic field.

Earth's crust core contains a large amount of iron and nickel is the evidence of the dynamo theory.

Para-amino salicylic acid (PAS) is used in the treatment of Tuberculosis.

Neeraj Chopra became the first Indian javelin thrower to claim a gold medal at the Commonwealth Games, with a season’s best effort of 86.47m in the final. The 20-year-old junior world champion had made the final after achieving the qualifying mark in his very first throw.