Question

Which one of the following statements regarding helium is incorrect? 

(a) It is used to fill gas in balloons instead of hydrogen because it is lighter and non-inflammable. 

(b) It is used as a cryogenic agent for carrying out experiments at low temperatures. 

(c) It is used to produce and sustain powerful superconducting magnets. 

(d) It is used in gas-cooled nuclear reactors.

Answer 1

(a) : Helium is twice as heavy as hydrogen, its lifting power is 92 percent of that of hydrogen. 

Helium has the lowest melting and boiling points of any element which makes liquid helium an ideal coolant for many extremely low-temperature applications such as superconducting magnets, and cryogenic research where temperatures close to absolute zero are needed.