ac

In a series, LCR-circuit, resonant frequency will be

• L/C

• $\sqrt{LC}$

• $\frac{1}{\sqrt{LC}}$

• $\sqrt{\frac{L}{C}}$

If an AC voltage is applied to an LCR circuit, which of the following is true?

• I and V are out of phase with each other in R.

• I and V are in phase in L while in C, they are out of phase.

• I and V are out of phase in both C and L.

• I and V are out of phase in L and in phase in C.

The peak value of ac voltage on a 220 V mains is

• $200\sqrt{2}$

• $220\sqrt{2}$

• $\frac{220}{\sqrt{2}}$

• 220

Series ac circuit has inductance L, resistance R and angular frequency to, the quality factor Q is

• $\left(\frac{\omega L}{R^{ }}\right)^2$

• $\frac{\omega L}{R}$

• $\frac{R}{\omega L}$

• $\left(\frac{R}{\omega L}\right)^2$

Choose the correct statement.

• In a dc circuit the inductor can conduct but not a capacitor.

• In dc circuit both the inductor and capacitor cannot conduct.

• The inductor has infinite resistance in a dc circuit.

• In a dc circuit capacitor has zero resistance

The reactance of a capacitor C is Xc. If both the frequency and capacitance be doubled, then new reactance will be

• Xc

• 2Xc

• 4Xc

• $\frac{Xc}{4}$

Average power generated in an inductor connected to an a.c. source is

• $\frac{1}{2\ }LI^2$

• VI

• Zero

• None of these

The power factor varies between

• 2 and 2.5

• 3.5 to 5

• 1 to 2

• 0 to 1

The phase relationship between current and voltage in a pure resistive circuit is best represented by

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Which of the following graphs represents the correct variation of inductive reactance XL with frequency u?

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