Q1:

What is the true power of a 24 Vac parallel RL circuit when R = 45 and X_L = 1100 ?

ANS:B - 12.8 W

Another way is total I * V.
There is a power dissipated in the resistor and also low lost in Inductor.
So both need to be considered !

In parallel circuit Total current It= IL +Ir but since they are not in the same phase so cannot plus directly.

It^2 = IL^2 + Ir^2.

Ir = V/R =24/45 = 0.533.
IL = V/Xl =24/1100 = 0.0218.

It = sqr(IL^2 +Ir^2) = sqr(0.5333*0.5333 +0.02182*0.02182) = 0.53345.

It = 0.53345 ampere.

Power = VIt = 24 * 0.5334 = 12.80 (more accurate).