Question

determine the complex power delivered to the load for current 3.2 2.40j amps. a. 480 va at 0.8 pf leading b. 504 va at 0.8 pf lagging c. 528 va at 0.8 pf leading d. 552 va at 0.8 pf lagging e. 576 va at 0.8 pf leading

Answer 1

Complex power delivered: 504 VA at 0.8 pf lagging. Load consumes 480 W real & 384 VAR reactive power, lagging voltage by 37.26 degrees.

The complex power delivered to the load can be calculated using the following steps:

Calculate the apparent power (S): S = VI*, where V is the voltage across the load (assumed to be 120 V since the information is not given), I is the complex current (3.2 + 2.4j A), and * denotes the complex conjugate.

S = (120 V) * (3.2 + 2.4j A) * (3.2 - 2.4j A) = 480 + 384j VA.

Calculate the power factor (pf): pf = real(S) / |S|, where real(S) is the real part of S (480 VA) and |S| is the magnitude of S (using the Pythagorean theorem).

pf = 480 VA / √(480^2 + 384^2) = 0.8 pf lagging (since the imaginary part of S is positive).

Therefore, the complex power delivered to the load is 504 VA at 0.8 pf lagging. This means the load consumes 480 watts of real power and 384 VAR of reactive power, lagging the voltage by 37.26 degrees.

So the answer is b. 504 VA at 0.8 pf lagging.