hi ,
A smd ressitor of 0.1W power rating can be supplied with 5v,2A??
What else constitutes the circuit? Is this a resistor on its own (i.e. the 5V 2A supply connected across it) or is the applied voltage/current passing through it to 'something else?
You can apply 1,000,000V and 1,000,000 amps to a 0.1W resistor provided there's nothing connected to the other end of it...... except, if there's no connection to the other end of that resistor then no current will flow in it.
More details needed please.