Which of the following gas can be used in Van de Graaff generator?

Van de Graaff generator is

Van de Graaff generator is

Van de Graff generator produces

Which of the following is used ain van Arkel method ?

Which of the following can be used to generate electricity?

Which of the following methods can be used to produce phosphine gas ?

Which of the following processes can be used for preparation of $H_2$ gas ?

Van de Graaff generator is used for

Van de Graaff generator is used for

Draw a labelled diagram of vande Graaff generator.