If you can read the amps you should also be able to read the watts (just turn the PSU by 90°).
Assuming you have a genuine Apple PSU (Apple logo directly in the plastic on both sides).
My 65W unit claims 2.65A so it does indeed seem that you have a 45W unit from an iBook.

[ Edited by Kronos 20.01.2013 - 21:12 ]