Question 473: AC fundamentals

Question

A resistance 'R' draws power 'P' when connected to an AC source. If an inductance is now placed in series with the resistance, such that the impedance of the circuit becomes 'Z'. the power drawn will be

Accepted Answer

For pure resistor circuit, power
P = $${{V_{rms}^2} \over R}$$
$$ \Rightarrow $$ $${V_{rms}^2}$$ = PR
For L-R series circuit, power
P' = V
rms
I
rms
cos$$\phi $$
= $${V_{rms}} 	imes {{{V_{rms}}} \over Z} 	imes {R \over Z}$$
= $${{V_{rms}^2R} \over {{Z^2}}}$$ = $${{PR 	imes R} \over {{Z^2}}}$$
$$ 	herefore $$ P' = $$P{\left( {{R \over Z}} ight)^2}$$

Answer

$$P\left( {{R \over Z}} \right)$$

Answer

P

Answer

$$P{\left( {{R \over Z}} \right)^2}$$

Answer

$$P\sqrt {{R \over Z}} $$

AC fundamentals

A resistance 'R' draws power 'P' when connected to an AC source. If an inductance is now placed in series with the resistance, such that the impedance of the circuit becomes 'Z'. the power drawn will be

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