Holds H1B and trying to get H4 visa and needs to travel on H4 visa

USA H1B Visa
1

Currently I holds H1B visa valid up to 2015 September and trying to get H4 visa. If I travels on H4 visa to US, will it effect my H1B visa in any way?

And if I travelled with H4 visa and can I do a job with H1 visa currently I holds, with out travelling back to India?

2

No, H-4 visa processing will not impact the H-1 processing.

After you enter on H-4 visa, you can apply for COS from H-4 to H-1. Once this is approved, you can start working on H-1 for the employer holding the H-1 petition.