EASY

Earn 100

An inductor of inductance $10 H$ is connected in series with a resistance $R = 6 Ω$ . A $12 volt$ battery is connected for a long time. When the circuit is switched off, calculate the induced emf in inductor, if current reduces to zero in $10 ms$ .

Important Questions on Alternating Current

MEDIUM

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

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:

EASY

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

For a given frequency, the inductive reactance of a coil at

100 H

25 Ω

. For the same frequency, the inductance reactance at

200 H

will be

EASY

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

A pure inductor of,

30.0 mH

is connected to a source of,

250 V

. Find the inductive reactance (in

Ω

) and R.M.S. current (in

A

) in the circuit if the frequency of the source is

80 Hz

EASY

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

Which device is used in series with a fluorescent lamp in an AC circuit?

EASY

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

A sinusoidal voltage with a frequency of

50 Hz

is applied to a series

L C R

circuit with a resistance of

5 Ω

, inductance of

20 mH

and a capacitance of

500 μ F

. The magnitude of impedance of the circuit is close to

MEDIUM

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

What is the inductive reactance? Shows how the purely inductive circuit offers zero resistance to direct current.

HARD

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

In the given circuit the $AC$ source has $ω = 100 rad s^{- 1}$ . Considering the inductor and capacitor to be ideal, what will be the current $I$ flowing through the circuit?

Question Image

EASY

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

The phase difference between voltage and current when an ac source is connected to an inductor. :

EASY

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

600 Hz

, an inductor and capacitor have equal reactances, the ratio of the capacitive reactance to the inductive reactance at

60 Hz

will be

EASY

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

Which of the following represents the variation of inductive reactance

(X_{L})

with the frequency of voltage source

(ν) ?

MEDIUM

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

Draw a labelled graph showing the variation of inductive reactance

(X_{L})

verses frequency

(f)

HARD

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

An inductance coil has a reactance of

100 Ω

. When an AC signal of frequency

1000 Hz

is applied to the coil, the applied voltage leads the current by

45 °

. The self-inductance of the coil is

MEDIUM

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

The phase difference between current and voltage in an A.C. circuit containing inductance only is.

EASY

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

When an inductor is connected to

200 V

dc voltage, a current of

1 A

flows through it. When the same inductor is connected to a

200 V

50 H z

ac source, only

0.5 A

current flows. Explain, why ? Also, calculate the self inductance of the inductor.

EASY

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

An applied

e . m . f .

signal consists of superposition of a d.c. source and a.c. source of high frequency. The circuit consists of an inductor

L

and a capacitor

C

in series. Show that d.c. signal appears across

C

and a.c. signal appears across

L

MEDIUM

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

Derive an expression for current $i$ passing through an AC circuit containing only inductor $L$ . Draw a phasor diagram and graph of $v$ and $i$ versus $ω t$ . Explain instantaneous power and the average power.

MEDIUM

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

What is the principle of choke coil? Why is the current in the choke coil called wattless current? Write its application in current control.

EASY

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

What happens to the inductive reactance and the current in a purely inductive circuit if the frequency is halved ?

EASY

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

Three identical emf sources are attached to a single circuit element: a resistor, a capacitor, or an inductor. The current amplitude is then measured as a function of frequency. Which one of the following curve corresponds to inductive circuit?

Question Image

EASY

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

A series

L R

circuit is connected to a voltage source with

V (t) = V_{0} \sin (ω t)

. After a very large time, current

I (t)

behaves as

(t_{0} ≫ \frac{L}{R})

An inductor of inductance 10 H is connected in series with a resistance R=6 Ω. A 12 volt battery is connected for a long time. When the circuit is switched off, calculate the induced emf in inductor, if current reduces to zero in 10 ms.

Important Questions on Alternating Current

Learn and Prepare for any exam you want !

An inductor of inductance $10 H$ is connected in series with a resistance $R = 6 Ω$ . A $12 volt$ battery is connected for a long time. When the circuit is switched off, calculate the induced emf in inductor, if current reduces to zero in $10 ms$ .