No, this value is very task specific. In some cases you want to extract 2D representation (e.g. for plotting) whatever the value of the explained variance (although it's good to check that value in retrospect to have an idea on how much the plot is lying to you).

Furthermore for LSA applications typically extract between 100 and 500 components. The explained variance ratio is around 25% to 50%. Despite this, similarity queries and clustering algorithms are reported to work well with such low numbers of components.