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The impedance of a series RC circuit varies directly with frequency.

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Important Questions on Alternating Current

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Physics>Electricity and Magnetism>Alternating Current>AC Voltage Applied to a Resistor

The peak current through a

200 mH

inductor connected to an

A C

source of peak value

210 V

and frequency

50 Hz

is ___.

EASY

Physics>Electricity and Magnetism>Alternating Current>AC Voltage Applied to a Resistor

AC

circuit has

R = 100 Ω, C = 2 μ F

and

L = 80 mH,

connected in series. The quality factor of the circuit is :

EASY

Physics>Electricity and Magnetism>Alternating Current>AC Voltage Applied to a Resistor

In the given circuit the peak voltages across $C, L$ and $R$ are $30 V, 110 V$ and $60 V$ respectively. The rms value of the applied voltage is

Question Image

EASY

Physics>Electricity and Magnetism>Alternating Current>AC Voltage Applied to a Resistor

An AC source is rated at

220 V, 50 Hz

. The time taken for voltage to change from its peak value to zero is

HARD

Physics>Electricity and Magnetism>Alternating Current>AC Voltage Applied to a Resistor

The instantaneous voltages at three terminals marked

X, Y

and

Z

are given by

V_{X} = V_{0} \sin ω t

V_{Y} = V_{0} \sin (ω t + \frac{2 π}{3})

and

V_{Z} = V_{0} \sin (ω t + \frac{4 π}{3}) .

An ideal voltmeter is configured to read rms value of the potential difference between its terminals. It is connected between points

X

and

Y

and then between

Y

and

Z

. The reading(s) of the voltmeter will be

EASY

Physics>Electricity and Magnetism>Alternating Current>AC Voltage Applied to a Resistor

The RMS value of emf given by

E = (8 \sin ω t + 6 \cos ω t)

volt is

MEDIUM

Physics>Electricity and Magnetism>Alternating Current>AC Voltage Applied to a Resistor

40 μF

capacitor is connected to a

200 V

50 Hz

AC supply. The rms value of the current in the circuit is, nearly:

EASY

Physics>Electricity and Magnetism>Alternating Current>AC Voltage Applied to a Resistor

The mean or average value of AC over a complete cycle is

MEDIUM

Physics>Electricity and Magnetism>Alternating Current>AC Voltage Applied to a Resistor

An alternating voltage

V (t) = 220 \sin (100 π t)

volt is applied to a purely resistive load of

50 Ω

. The time taken for the current to rise from half of the peak value to the peak value is:

MEDIUM

Physics>Electricity and Magnetism>Alternating Current>AC Voltage Applied to a Resistor

An alternating voltage is given by $E = 100 \sin (ω t + \frac{π}{6}) V$ . The voltage will be maximum for the first time when time is ( $T =$ time period)

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Physics>Electricity and Magnetism>Alternating Current>AC Voltage Applied to a Resistor

The rms value of potential difference $V_{0}$ shown in figure is

Question Image

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Physics>Electricity and Magnetism>Alternating Current>AC Voltage Applied to a Resistor

Out of the following graphs, which graph shows the correct relation (graphical representation) for LC Parallel resonant circuit?

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Physics>Electricity and Magnetism>Alternating Current>AC Voltage Applied to a Resistor

In Karnataka, the normal domestic

AC

power supply is rated as

220 V

50 Hz

. Here

220 V

and

50 Hz

refer to:

EASY

Physics>Electricity and Magnetism>Alternating Current>AC Voltage Applied to a Resistor

In the circuit shown below, if $V_{s} = V_{m} \sin ω t$ and the diode is ideal, the average value of voltage across $R_{L}$ is (Assume source resistance is zero)

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MEDIUM

Physics>Electricity and Magnetism>Alternating Current>AC Voltage Applied to a Resistor

100 W

bulb is connected to an

AC

source of

220 V, 50 Hz

. Then the current flowing through the bulb is

EASY

Physics>Electricity and Magnetism>Alternating Current>AC Voltage Applied to a Resistor

What is

r . m . s .

value of a.c.?

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Physics>Electricity and Magnetism>Alternating Current>AC Voltage Applied to a Resistor

An alternating current is given by the equation

i = i_{1} \sin ω t + i_{2} \cos ω t

. The rms current will be:

EASY

Physics>Electricity and Magnetism>Alternating Current>AC Voltage Applied to a Resistor

The frequency of an alternating current is

50 Hz

. What is the minimum time taken by current to reach its peak value from zero value?

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Physics>Electricity and Magnetism>Alternating Current>AC Voltage Applied to a Resistor

When the rms voltages

V_{L}, V_{C}

and

V_{R}

are measured respectively across the inductor

L,

the capacitor

C

and the resistor

R

in a series

L C R

circuit connected to an

A C

source, it is found that the ratio

V_{L} : V_{C} : V_{R} = 1 : 2 : 3.

If the rms voltage of the

A C

source is

100 V,

then

V_{R}

is close to :

EASY

Physics>Electricity and Magnetism>Alternating Current>AC Voltage Applied to a Resistor

The AC voltage across a resistance can be measured using a:

The impedance of a series RC circuit varies directly with frequency.

Important Questions on Alternating Current

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