I have searched answer for this question .. But i found one solution in SO .. One user had suggested to use padding-left or this qustion.
<select>
<option>one</option>
<option>one-two</option>
</select>
When i add padding-left it works fine with the browser .. When i check my dropdown in devices , its not aligned at the center as i expected .. I have given values for padding-left in percentage and pixels also .. Is there any other way to do it so that it works fine in all browsers and devices??