If the resistance doubles while the voltage stays the same, what effect will that have on the power?

Power n an electrical circuit is given by  P=IV  and and therefore R= V²/P    from the above equation , thee resistance R, is inversely proportional to the power P,  at constant power P.

Therefore if we double the resistance R, the power will reduce by half. Meaning if we are having a power of 100 watts and we double the resistance at constant voltage the power will reduce to half.