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Chose the correct phasor diagram for a purely resistive a.c. circuit.

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

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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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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

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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:

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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

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

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

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

A . C .

voltage

V = 5 \cos (1000 t) V

is applied to a

L - R

series circuit of inductance

3 mH

and resistance

4 Ω .

The value of maximum current in the circuit is _____

A

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

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

A C

current is given by

I = I_{1} s i n ω t + I_{2} c o s ω t .

A hot wire ammeter will give a reading:

EASY

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

A C

source rated

220 V, 50 Hz

is connected to a resistor. The time taken by the current to change from its maximum to the rms value is :

EASY

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:

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

For an

AC

given by

I = 50 \cos (100 t + 45 °) A

. The value of

I_{rms} =_________A

EASY

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

A bulb of resistance

280 Ω

is supplied with a

200 V

A C

supply. What is the peak current?

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

If the mains voltage is

230 V

, then the peak voltage approximately is

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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

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:

Chose the correct phasor diagram for a purely resistive a.c. circuit.

Important Questions on Alternating Current

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