I have a valid stamped H1 B visa, Can I apply for H4 and travel on H4 visa?

I have a valid H1 B visa stamped for 3 yrs in starting from Oct 2014, But due to LCA issues, I was unable to travel to required location.

Hence I planned to apply H4 and travel on H4.

Will I have questions if I apply H4 when I have a valid H1 visa?