Question 51: AC fundamentals

Question

For a series L-C-R circuit at resonance, which statement is not true?

Accepted Answer

In L-C-R series resonance circuit,
$${X_L} = {X_C}$$
$$	herefore$$ Impedance, $$Z = \sqrt {{R^2} + {{({X_L} - {X_C})}^2}}  = \sqrt {{R^2} + {0^2}} $$
$$ \Rightarrow Z = R$$
$$	herefore$$ Power factor, $$\cos \phi  = {R \over Z} = {R \over R} = 1$$
Which is not zero.
Since, circuit behaves likes a resistive circuit. So, power loss occurs always in this circuits.
i.e. wattless current is zero.

Answer

Wattless current is zero.

Answer

Power factor is zero.

Answer

Peak energy stored by a capacitor = peak energy stored by an inductor.

Answer

Average power = apparent power.

AC fundamentals

For a series L-C-R circuit at resonance, which statement is not true?

Choose the correct answer: