please can anyone tell me... why the larger resistor in size can
safely dissipate without suffering damage???? thanx in advance for all who can help

 

That is a good question.

You wouldn't use a small nail for a big job. Nor would you hit a small nail with a big hammer or a big nail with a small hammer.

My guess is that a physically bigger resistor can withstand more physical stress.

The other answer is the temperature rise. A larger resistor has more thermal capacity and hence the temperature rise would be lower.