## Alternating Current and Electromagnetic Induction

### Physics

#### Previous Years Questions

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For the given circuit the current i through the battery when the key in closed and the steady state has been reached is ...
JEE Main 2021 (Online) 1st September Evening Shift
Statement - I :To get a steady dc output from the pulsating voltage received from a full wave rectifier we can connect a...
JEE Main 2021 (Online) 31st August Evening Shift
In an ac circuit, an inductor, a capacitor and a resistor are connected in series with XL = R = XC. Impedance of this ci...
JEE Main 2021 (Online) 31st August Morning Shift
A small square loop of side 'a' and one turn is placed inside a larger square loop of side b and one turn (b &gt;&gt; a)...
JEE Main 2021 (Online) 31st August Morning Shift
Electric field in a plane electromagnetic wave is given by E = 50 sin(500x $$-$$ 10 $$\times$$ 1010 t) V/m The velocity ...
JEE Main 2021 (Online) 27th August Morning Shift
In the given circuit the AC source has $$\omega$$ = 100 rad s-1. Considering the inductor and capacitor to be ideal, wha...
JEE Main 2021 (Online) 26th August Evening Shift
A series LCR circuit driven by 300 V at a frequency of 50 Hz contains a resistance R = 3 k$$\Omega$$, an inductor of ind...
JEE Main 2021 (Online) 26th August Morning Shift
An inductor coil stores 64 J of magnetic field energy and dissipates energy at the rate of 640 W when a current of 8A is...
JEE Main 2021 (Online) 26th August Morning Shift
A 100$$\Omega$$ resistance, a 0.1 $$\mu$$F capacitor and an inductor are connected in series across a 250 V supply at va...
JEE Main 2021 (Online) 27th July Evening Shift
A 0.07 H inductor and a 12$$\Omega$$ resistor are connected in series to a 220V, 50 Hz ac source. The approximate curren...
JEE Main 2021 (Online) 27th July Morning Shift
A 10 $$\Omega$$ resistance is connected across 220V $$-$$ 50 Hz AC supply. The time taken by the current to change from ...
JEE Main 2021 (Online) 25th July Evening Shift
Match List - I with List - II List - I List - II (a) $$\omega L &gt; {1 \over {\om... JEE Main 2021 (Online) 22th July Evening Shift In a circuit consisting of a capacitance and a generator with alternating emf Eg = Eg0 sin$$\omega$$t, VC and IC are the... JEE Main 2021 (Online) 22th July Evening Shift For a series LCR circuit with R = 100$$\Omega$$, L = 0.5 mH and C = 0.1 pF connected across 220V$$-$$50 Hz AC supply, t... JEE Main 2021 (Online) 20th July Evening Shift The time taken for the magnetic energy to reach 25% of its maximum value, when a solenoid of resistance R, inductance L ... JEE Main 2021 (Online) 18th March Evening Shift In a series LCR circuit, the inductive reactance (XL) is 10$$\Omega$$and the capacitive reactance (XC) is 4$$\Omega$$. ... JEE Main 2021 (Online) 18th March Evening Shift An AC source rated 220 V, 50 Hz is connected to a resistor. The time taken by the current to change from its maximum to ... JEE Main 2021 (Online) 18th March Morning Shift In a series LCR resonance circuit, if we change the resistance only, from a lower to higher value : JEE Main 2021 (Online) 18th March Morning Shift What happens to the inductive reactance and the current in a purely inductive circuit if the frequency is halved? JEE Main 2021 (Online) 17th March Evening Shift Match List - I with List - II List - I List - II (a) Phase difference between curr... JEE Main 2021 (Online) 17th March Evening Shift An AC current is given by I = I1 sin$$\omega$$t + I2 cos$$\omega$$t. A hot wire ammeter will give a reading :... JEE Main 2021 (Online) 17th March Morning Shift For the given circuit, comment on the type of transformer used.... JEE Main 2021 (Online) 16th March Evening Shift An RC circuit as shown in the figure is driven by a AC source generating a square wave. The output wave pattern monitore... JEE Main 2021 (Online) 16th March Morning Shift Find the peak current and resonant frequency of the following circuit (as shown in figure).... JEE Main 2021 (Online) 26th February Evening Shift An alternating current is given by the equation i = i1 sin$$\omega$$t + i2 cos$$\omega$$t. The rms current will be :... JEE Main 2021 (Online) 26th February Morning Shift Match List I with List II. List I List II (a) Rectifier (i) Used either fo... JEE Main 2021 (Online) 25th February Evening Shift An LCR circuit contains resistance of 110$$\Omega$$and a supply of 220 V at 300 rad/s angular frequency. If only capaci... JEE Main 2021 (Online) 25th February Evening Shift The current (i) at time t = 0 and t =$$\infty $$respectively for the given circuit is :... JEE Main 2021 (Online) 25th February Morning Slot The angular frequency of alternating current in a L-C-R circuit is 100 rad/s. The components connected are shown in the ... JEE Main 2021 (Online) 25th February Morning Slot Figure shows a circuit that contains four identical resistors with resistance R = 2.0$$\Omega$$, two identical inductors... JEE Main 2021 (Online) 24th February Evening Slot An AC circuit has R= 100$$\Omega $$, C = 2$$\mu $$F and L = 80 mH, connected in series. The quality factor of the circ... JEE Main 2020 (Online) 6th September Morning Slot A series L-R circuit is connected to a battery of emf V. If the circuit is switched on at t = 0, then the time at which ... JEE Main 2020 (Online) 4th September Evening Slot Choose the correct option relating wave lengths of different parts of electromagnetic wave spectrum: JEE Main 2020 (Online) 4th September Morning Slot The electric field of a plane electromagnetic wave propagating along the x direction in vacuum is$$\overrightarrow E =...
JEE Main 2020 (Online) 3rd September Evening Slot
The magnetic field of a plane electromagnetic wave is $$\overrightarrow B = 3 \times {10^{ - 8}}\sin \left[ {200\pi \le... JEE Main 2020 (Online) 3rd September Morning Slot An inductance coil has a reactance of 100$$\Omega $$. When an AC signal of frequency 1000 Hz is applied to the coil, th... JEE Main 2020 (Online) 2nd September Evening Slot In a plane electromagnetic wave, the directions of electric field and magnetic field are represented by$$\widehat k$$a... JEE Main 2020 (Online) 2nd September Evening Slot A plane electromagnetic wave, has frequency of 2.0$$ \times $$1010 Hz and its energy density is 1.02$$ \times $$10–8... JEE Main 2020 (Online) 2nd September Morning Slot A LCR circuit behaves like a damped harmonic oscillator. Comparing it with a physical spring-mass damped oscillator havi... JEE Main 2020 (Online) 7th January Morning Slot A long solenoid of radius R carries a time (t) - dependent current I(t)=I0t(1 - t). A ring of radius 2R is placed coaxia... JEE Main 2020 (Online) 7th January Morning Slot Consider a circular coil of wire carrying constant current I, forming a magnetic dipole. The magnetic flux through an in... JEE Main 2020 (Online) 7th January Morning Slot A plane electromagnetic wave having a frequency v = 23.9 GHz propagates along the positive z-direction in free space. Th... JEE Main 2019 (Online) 12th April Evening Slot The electric field of a plane electromagnetic wave is given by$$\overrightarrow E = {E_0}\widehat i\cos (kz)cos(\omega...
JEE Main 2019 (Online) 10th April Morning Slot
The total number of turns and cross-section area in a solenoid is fixed. However, its length L is varied by adjusting th...
JEE Main 2019 (Online) 9th April Morning Slot
A paramagnetic material has 1028 atoms/m3. Its magnetic susceptibility at temperature 350 K is 2.8 $$\times$$ 10–4. It...
JEE Main 2019 (Online) 12th January Evening Slot
A 10 m long horizontal wire extends from North East to South West. It is falling with a speed of 5.0 ms–1, at right angl...
JEE Main 2019 (Online) 12th January Evening Slot
A paramagnetic substance in the form of a cube with sides 1 cm has a magnetic dipole moment of 20 $$\times$$ 10–6 J/ T...
JEE Main 2019 (Online) 11th January Evening Slot
A 27 mW laser beam has a cross-sectional area of 10 mm2. The magnitude of the maximum electric field in this electromagn...
JEE Main 2019 (Online) 11th January Evening Slot
An electromagnetic wave of intensity 50 Wm–2 enters in a medium of refractive index 'n' without any loss. The ratio of t...
JEE Main 2019 (Online) 11th January Morning Slot
The electric field of a plane polarized electromagnetic wave in free space at time t = 0 is given by an expression $$\ov... JEE Main 2019 (Online) 10th January Evening Slot The self induced emf of a coil is 25 volts. When the current in it is changed at uniform rate from 10 A to 25 A in 1s, t... JEE Main 2019 (Online) 10th January Evening Slot If the magnetic field of a plane electromagnetic wave is given by (the speed of light = 3 × 108 B = 100 × 10–6 sin$$\l...
JEE Main 2019 (Online) 10th January Morning Slot
A power transmission line feeds input power at 2300 V to a srep down transformer with its primary windings having 4000 t...
JEE Main 2019 (Online) 9th January Evening Slot
A plane electromagnetic wave of wavelength $$\lambda$$ has an intensity I. It is propagatting along the positive Y-dir...
JEE Main 2018 (Online) 16th April Morning Slot
A power transmission line feeds input power at 2300 V to a step down transformer with its primary windings having 4000 t...
JEE Main 2018 (Online) 16th April Morning Slot
A coil of cross-sectional area A having n turns is placed in a uniform magnetic field B. When it is rotated with an angu...
JEE Main 2018 (Online) 16th April Morning Slot
A plane polarized monochromatic EM wave is traveling in vacuum along z direction such that at t = t1 it is found that th...
JEE Main 2018 (Online) 15th April Evening Slot
At the center of a fixed large circular coil of radius R, a much smaller circular coil of radius r is placed. The two co...
JEE Main 2018 (Online) 15th April Evening Slot
A copper rod of mass m slides under gravity on two smooth parallel rails, with separation l and set at an angle of $$\t... JEE Main 2018 (Online) 15th April Evening Slot An ideal capacitor of capacitance$$0.2\,\mu F$$is charged to a potential difference of$$10V.$$The charging batt... JEE Main 2018 (Online) 15th April Morning Slot A monochromatic beam of light has a frequency$$v = {3 \over {2\pi }} \times {10^{12}}Hz$$and is propagating along the ... JEE Main 2018 (Online) 15th April Morning Slot An EM wave from air enters a medium. The electric fields are$$\overrightarrow {{E_1}} $$=$${E_{01}}\widehat x\cos \le...
JEE Main 2018 (Offline)
For an RLC circuit driven with voltage of amplitude vm and frequency $${\omega _0}$$ = $${1 \over {\sqrt {LC} }}$$ the c...
JEE Main 2018 (Offline)
In an a.c. circuit, the instantaneous e.m.f. and current are given by e = 100 sin 30 t i = 20 sin $$\left( {30t - {\pi ... JEE Main 2018 (Offline) The electric field component of a monochromatic radiation is given by$$\overrightarrow E $$= 2 E0$$\widehat i$$cos k... JEE Main 2017 (Online) 9th April Morning Slot A sinusoidal voltage of peak value 283 V and angular frequency 320/s is applied to a series LCR circuit. Given that R=5 ... JEE Main 2017 (Online) 9th April Morning Slot A small circular loop of wire of radius a is located at the centre of a much larger circular wire loop of radius b. The ... JEE Main 2017 (Online) 8th April Morning Slot In a coil of resistance 100$$\Omega $$, a current is induced by changing the magnetic flux through it as shown in the f... JEE Main 2017 (Offline) An arc lamp requires a direct current of 10 A at 80 V to function. If it is connected to a 220 V (rms), 50 Hz AC supply,... JEE Main 2016 (Offline) Consider an electromagnetic wave propagating in vacuum. Choose the correct statement : JEE Main 2016 (Online) 10th April Morning Slot A conducting metal circular-wire-loop of radius r is placed perpendicular to a magnetic field which varies with time as ... JEE Main 2016 (Online) 10th April Morning Slot A series LR circuit is connected to a voltage source with V(t) = V0 sin$$\Omega $$t. After very large time, current I(... JEE Main 2016 (Online) 9th April Morning Slot Microwave oven acts on the principle of : JEE Main 2016 (Online) 9th April Morning Slot A red$$LED$$emits light at$$0.1$$watt uniformly around it. The amplitude of the electric field of the light at a dis... JEE Main 2015 (Offline) An inductor$$(L=0.03H)$$and a resistor$$\left( {R = 0.15\,k\Omega } \right)$$are connected in series to a batte... JEE Main 2015 (Offline) An$$LCR$$circuit is equivalent to a damped pendulum. In an$$LCR$$circuit the capacitor is charged to$${Q_0}$$and t... JEE Main 2015 (Offline) An arc lamp requires a direct current of$$10A$$at$$80V$$to function. If it is connected to a$$220V$$... JEE Main 2015 (Offline) Two coaxial solenoids of different radius carry current$$I$$in the same direction.$$\overrightarrow {{F_1}} $$be the... JEE Main 2015 (Offline) Match List -$$1$$(Electromagnetic wave type ) with List -$$2$$(Its association/application) and select the correct ... JEE Main 2014 (Offline) During the propagation of electromagnetic waves in a medium: JEE Main 2014 (Offline) In the circuit shown here, the point$$'C'$$is kept connected to point$$'A'$$till the current flowing through the ci... JEE Main 2014 (Offline) The magnetic field in a travelling electromagnetic wave has a peak value of$$20nT$$. The peak value of electri... JEE Main 2013 (Offline) In an$$LCR$$circuit as shown below both switches are open initially. Now switch$${S_1}$$is closed,$${S_2}$$kept op... JEE Main 2013 (Offline) A metallic rod of length$$'\ell '$$is tied to a string of length$$2\ell $$and made to rotate with angular speed... JEE Main 2013 (Offline) A circular loop of radius$$0.3cm$$lies center of the small loop is on the axis of the bigger loop. The distance b... JEE Main 2013 (Offline) A coil is suspended in a uniform magnetic field, with the plane of the coil parallel to the magnetic lines of force. Whe... AIEEE 2012 A resistor$$'R'$$and$$2\mu F$$capacitor in series is connected through a switch to$$200V$$direct supply. Acro... AIEEE 2011 A boat is moving due east in a region where the earth's magnetic fields is$$5.0 \times {10^{ - 5}}N{A^{ - 1}}\,{m^...
AIEEE 2011
A fully charged capacitor $$C$$ with initial charge $${q_0}$$ is connected to a coil of self inductance $$L$$ at $$t=0.... AIEEE 2011 In the circuit shown below, the key$$K$$is closed at$$t=0.$$The current through the battery is ... AIEEE 2010 A rectangular loop has a sliding connector$$PQ$$of length$$l$$and resistance$$R\Omega $$and it is moving with... AIEEE 2010 In a series$$LCR$$circuit$$R = 200\Omega $$and the voltage and the frequency of the main supply is$$220V$$and$$50...
AIEEE 2010
An inductor of inductance $$L=400$$ $$mH$$ and resistors of resistance $${R_1} = 2\Omega$$ and $${R_2} = 2\Omega$$ are...
AIEEE 2009
Two coaxial solenoids are made by winding thin insulated wire over a pipe of cross-sectional area $$A=$$ $$10\,\,c{m^2}... AIEEE 2008 An ideal coil of$$10H$$is connected in series with a resistance of$$5\Omega $$and a battery of$$5V$$.$$2$$second ... AIEEE 2007 In an$$a.c.$$circuit the voltage applied is$$E = {E_0}\,\sin \,\omega t.$$The resulting current in the circuit is$$...
AIEEE 2007
The $$rms$$ value of the electric field of the light coming from the Sun is $$720$$ $$N/C.$$ The average total energy de...
AIEEE 2006
An inductor $$(L=100$$ $$mH)$$, a resistor $$\left( {R = 100\,\Omega } \right)$$ and a battery $$\left( {E = 100V} \righ... AIEEE 2006 The flux linked with a coil at any instant$$'t'$$is given by$$\phi = 10{t^2} - 50t + 250$$The induced$$emf$$at ... AIEEE 2006 In an$$AC$$generator, a coil with$$N$$turns, all of the same area$$A$$and total resistance$$R,$$rotates with fre... AIEEE 2006 In a series resonant$$LCR$$circuit, the voltage across$$R$$is$$100$$volts and$$R = 1\,k\Omega $$with$$C = 2\mu ...
AIEEE 2006
Which of the following units denotes the dimension $${{M{L^2}} \over {{Q^2}}}$$, where $$Q$$ denotes the electric charge...
AIEEE 2006
One conducting $$U$$ tube can slide inside another as shown in figure, maintaining electrical contacts between the tubes...
AIEEE 2005
The phase difference between the alternating current and $$emf$$ is $${\pi \over 2}.$$ Which of the following cannot be...
AIEEE 2005
A circuit has a resistance of $$12$$ $$ohm$$ and an impedance of $$15$$ $$ohm$$. The power factor of the circuit will be...
AIEEE 2005
A coil of inductance $$300$$ $$mH$$ and resistance $$2\,\Omega$$ is connected to a source of voltage $$2$$ $$V$$. The c...
AIEEE 2005
The self inductance of the motor of an electric fan is $$10$$ $$H$$. In order to impart maximum power at $$50$$ $$Hz$$, ...
AIEEE 2005
In a $$LCR$$ circuit capacitance is changed from $$C$$ to $$2$$ $$C$$. For the resonant frequency to remain unchaged, th...
AIEEE 2004
A metal conductor of length $$1$$ $$m$$ rotates vertically about one of its ends at angular velocity $$5$$ radians per ...
AIEEE 2004
In a uniform magnetic field of induction $$B$$ a wire in the form of a semicircle of radius $$r$$ rotates about the diam...
AIEEE 2004
A coil having $$n$$ turns and resistance $$R\Omega$$ is connected with a galvanometer of resistance $$4R\Omega .$$ This...
AIEEE 2004
In an $$LCR$$ series $$a.c.$$ circuit, the voltage across each of the components, $$L,C$$ and $$R$$ is $$50V$$. The volt...
AIEEE 2004
Alternating current can not be measured by $$D.C.$$ ammeter because
AIEEE 2004
The core of any transformer is laminated so as to
AIEEE 2003
When the current changes from $$+ 2A$$ to $$-2A$$ in $$0.05$$ second, an $$e.m.f.$$ of $$8$$ $$V$$ is inducted in a coi...
AIEEE 2003
In an oscillating $$LC$$ circuit the maximum charge on the capacitor is $$Q$$. The charge on the capacitor when the ener...
AIEEE 2003
Two coils are placed close to each other. The mutual inductance of the pair of coils depends upon
AIEEE 2003
Which of the following are not electromagnetic waves?
AIEEE 2002
A conducting square loop of side $$L$$ and resistance $$R$$ moves in its plane with a uniform velocity $$v$$ perpendicul...
AIEEE 2002
The inductance between $$A$$ and $$D$$ is ...
AIEEE 2002
In a transformer, number of turns in the primary coil are $$140$$ and that in the secondary coil are $$280.$$ If current...
AIEEE 2002
The power factor of $$AC$$ circuit having resistance $$(R)$$ and inductance $$(L)$$ connected in series and an angular v...
AIEEE 2002

## Numerical

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At very high frequencies, the effective impendence of the given circuit will be ________________ $$\Omega$$....
JEE Main 2021 (Online) 31st August Evening Shift
An ac circuit has an inductor and a resistor resistance R in series, such that XL = 3R. Now, a capacitor is added in ser...
JEE Main 2021 (Online) 27th August Evening Shift
The alternating current is given by $$i = \left\{ {\sqrt {42} \sin \left( {{{2\pi } \over T}t} \right) + 10} \right\}A$$...
JEE Main 2021 (Online) 27th August Morning Shift
In the given figure the magnetic flux through the loop increases according to the relation $$\phi$$B(t) = 10t2 + 20t, wh...
JEE Main 2021 (Online) 27th July Evening Shift
Two circuits are shown in the figure (a) &amp; (b). At a frequency of ____________ rad/s the average power dissipated in...
JEE Main 2021 (Online) 25th July Evening Shift
An inductor of 10 mH is connected to a 20V battery through a resistor of 10 k$$\Omega$$ and a switch. After a long time,...
JEE Main 2021 (Online) 25th July Morning Shift
A series LCR circuit of R = 5$$\Omega$$, L = 20 mH and C = 0.5 $$\mu$$F is connected across an AC supply of 250 V, havin...
JEE Main 2021 (Online) 20th July Evening Shift
In an LCR series circuit, an inductor 30 mH and a resistor 1 $$\Omega$$ are connected to an AC source of angular frequen...
JEE Main 2021 (Online) 20th July Morning Shift
A sinusoidal voltage of peak value 250 V is applied to a series LCR circuit, in which R = 8$$\Omega$$, L = 24 mH and C =...
JEE Main 2021 (Online) 16th March Morning Shift
In a series LCR resonant circuit, the quality factor is measured as 100. If the inductance is increased by two fold and ...
JEE Main 2021 (Online) 26th February Morning Shift
A transmitting station releases waves of wavelength 960 m. A capacitor of 2.56 $$\mu$$F is used in the resonant circuit....
JEE Main 2021 (Online) 25th February Morning Slot
A coil of inductance 2 H having negligible resistance is connected to a source of supply whose voltage is given by V = 3...
JEE Main 2021 (Online) 25th February Morning Slot
A series L-C-R circuit is designed to resonate at an angular frequency $$\omega$$0 = 105 rad/s. The circuit draws 16W po...
JEE Main 2021 (Online) 24th February Evening Slot
A resonance circuit having inductance and resistance 2 $$\times$$ 10$$-$$4 H and 6.28$$\Omega$$ respectively oscillates ...
JEE Main 2021 (Online) 24th February Morning Slot
A common transistor radio set requires 12 V (D.C.) for its operation. The D.C. source is constructed by using a transfor...
JEE Main 2021 (Online) 24th February Morning Slot
In a series LR circuit, power of 400W is dissipated from a source of 250 V, 50 Hz. The power factor of the circuit is 0....
JEE Main 2020 (Online) 6th September Evening Slot
In a fluorescent lamp choke (a small transformer) 100 V of reverse voltage is produced when the choke current changes un...
JEE Main 2020 (Online) 9th January Morning Slot
A loop ABCDEFA of straight edges has six corner points A(0, 0, 0), B(5, 0, 0), C(5, 5, 0), D (0, 5, 0), E(0, 5, 5) and F...
JEE Main 2020 (Online) 7th January Morning Slot

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