Facet - default value with search api I am using content type in Facet. The search result will be having an option to choose the content type to filter the result. 

I want the search should show the result with particular content-type filtered by default. Is it possible? If so, how to do that?

To be little more clear instead of

https://example.com/searchpage?search_terms=xxxx

I want to search as following by default. 

https://example.com/searchpage?search_terms=xxxx&amp;f[0]=content_type:content_page&amp;f[1]=content_type:cotent_page
Not sure you can do this with facets.  Facets by definition show only options that exist in the current query results.  There is no guarantee that a content_page type will be among the search results for a term. 

You may want to consider using an exposed view filter (the views_block_filter_block module lets you turn this into a place-able block).  This would show all content types and can have a default type selected if the filter has none.