Quiz - physics - Electromagnetic Induction-PYQ

Q1. A circular disc of radius 0.2 meter is placed in a uniform magnetic field of induction $\frac{1}{\pi^2}$ Wb/m² in such a way that its axis makes an angle of 60° with $\vec{B}$. The magnetic flux linked with the disc is Source: orcusprep.in

AIPMT 2008

medium

0.02 Wb

0.08 Wb

0.01 Wb

0.06 Wb

Q2. A 800 turn coil of effective area 0.05 m² is kept perpendicular to a magnetic field 5 × 10⁻⁵ T. When the plane of the coil is rotated by 90° around any of its coplanar axis in 0.1 s, the emf induced in the coil will be Source: orcusprep.in

NEET 2019

medium

0.02 V

2 V

0.2 V

2 × 10⁻³ V

Q3. A uniform magnetic field is restricted within a region of radius r. The magnetic field changes with time at a rate dB/dt. Loop 1 of radius R > r encloses the region r and loop 2 of radius R is outside the region of magnetic field as shown in the figure. Then the e.m.f. generated is Source: orcusprep.in

NEET 2016

hard

$-\frac{dB}{dt}\pi r^2$ in loop 1 and zero in loop 2

zero in loop 1 and zero in loop 2

$-\frac{dB}{dt}\pi R^2$ in loop 1 and zero in loop 2

$-\frac{dB}{dt}\pi r^2$ in loop 1 and $-\frac{dB}{dt}\pi r^2$ in loop 2

Q4. A coil of resistance 400 Ω is placed in a magnetic field. If the magnetic flux φ (Wb) linked with the coil varies with time t (sec) as φ = 50t² + 4. The current in the coil at t = 2 sec is Source: orcusprep.in

AIPMT 2012

medium

0.5 A

0.1 A

2 A

1 A

Q5. A conducting circular loop is placed in a uniform magnetic field, B = 0.025 T with its plane perpendicular to the loop. The radius of the loop is made to shrink at a constant rate of 1 mm s⁻¹. The induced emf when the radius is 2 cm, is Source: orcusprep.in

AIPMT 2010

medium

π μV

2π mV

π/2 μV

2 mV

Q6. A rectangular, a square, a circular and an elliptical loop, all in the (x-y) plane, are moving out of a uniform magnetic field with a constant velocity $\vec{V} = v\hat{i}$. The magnetic field is directed along the negative z axis direction. The induced emf, during the passage of these loops, out of the field region, will not remain constant for Source: orcusprep.in

AIPMT 2009

medium

the circular and the elliptical loops

only the elliptical loop

any of the four loops

the rectangular, circular and elliptical loops

Q7. A conducting circular loop is placed in a uniform magnetic field 0.04 T with its plane perpendicular to the magnetic field. The radius of the loop starts shrinking at 2 mm/s. The induced emf in the loop when the radius is 2 cm is Source: orcusprep.in

AIPMT 2009

medium

3.2π μV

4.8π mV

0.8π mV

1.6π mV

Q8. As a result of change in the magnetic flux linked to the closed loop as shown in the figure, an e.m.f. V volt is induced in the loop. The work done (joule) in taking a charge Q coulomb once along the loop is Source: orcusprep.in

AIPMT 2005

easy

QV

2QV

QV/2

zero

Q9. A rectangular coil of 20 turns and area of cross-section 25 sq. cm has a resistance of 100 Ω. If a magnetic field which is perpendicular to the plane of coil changes at a rate of 1000 tesla per second, the current in the coil is Source: orcusprep.in

AIPMT 1992

medium

0.5 A

1 A

50 A

5 A

Q10. A magnetic field of 2 × 10⁻² T acts at right angles to a coil of area 100 cm², with 50 turns. The average e.m.f. induced in the coil is 0.1 V, when it is removed from the field in t sec. The value of t is Source: orcusprep.in

AIPMT 1991

medium

0.1 s

10 s

0.01 s

1 s

Q11. An electron moves on a straight line path XY as shown. The abcd is a coil adjacent to the path of electron. What will be the direction of current, if any, induced in the coil? Source: orcusprep.in

AIPMT 2015

medium

The current will reverse its direction as the electron goes past the coil

No current induced

abcd

adcb

Q12. A metal ring is held horizontally and bar magnet is dropped through the ring with its length along the axis of the ring. The acceleration of the falling magnet is Source: orcusprep.in

AIPMT 1996

medium

less than g

more than g

equal to g

either (a) or (c)

Q13. Faraday's laws are consequence of conservation of Source: orcusprep.in

AIPMT 1991

easy

energy

energy and magnetic field

charge

magnetic field

Q14. A cycle wheel of radius 0.5 m is rotated with constant angular velocity of 10 rad/s in a region of magnetic field of 0.1 T which is perpendicular to the plane of the wheel. The EMF generated between its centre and the rim is Source: orcusprep.in

NEET 2019

medium

0.125 V

0.25 V

0.5 V

zero

Q15. A conducting square frame of side 'a' and a long straight wire carrying current I are located in the same plane as shown in the figure. The frame moves to the right with a constant velocity 'V'. The emf induced in the frame will be proportional to Source: orcusprep.in

AIPMT 2015

hard

$\frac{1}{x^2} - \frac{1}{(x+a)^2}$

$\frac{1}{(x+a)^2}$

$\frac{1}{x^2}$

$\frac{1}{(x-a)^2}$

Q16. A thin semicircular conducting ring (PQR) of radius r is falling with its plane vertical in a horizontal magnetic field B, as shown in the figure. The potential difference developed across the ring when its speed is v, is Source: orcusprep.in

AIPMT 2014

hard

2rBv and R is at higher potential

zero

Bvπr²/2 and P is at higher potential

πrBv and R is at higher potential

Q17. A straight line conductor of length 0.4 m is moved with a speed of 7 m/s perpendicular to a magnetic field of intensity 0.9 Wb/m². The induced e.m.f. across the conductor is Source: orcusprep.in

AIPMT 1995

easy

2.52 V

5.04 V

25.2 V

1.26 V

Q18. A long solenoid of diameter 0.1 m has 2 × 10⁴ turns per meter. At the centre of the solenoid, a coil of 100 turns and radius 0.01 m is placed with its axis coinciding with the solenoid axis. The current in the solenoid reduces at a constant rate to 0 A from 4 A in 0.05 s. If the resistance of the coil is 10π² Ω, the total charge flowing through the coil during this time is Source: orcusprep.in

NEET 2017

hard

32 μC

16 μC

16π μC

32π μC

Q19. In a coil of resistance 10 Ω, the induced current developed by changing magnetic flux through it, is shown in figure as a function of time. The magnitude of change in flux through the coil in weber is Source: orcusprep.in

AIPMT 2012

medium

2

8

6

4

Q20. The magnetic flux through a circuit of resistance R changes by an amount Δφ in a time Δt. Then the total quantity of electric charge Q that passes any point in the circuit during the time Δt is represented by Source: orcusprep.in

AIPMT 2004

easy

Q = Δφ/R

Q = R × Δφ/Δt

Q = Δφ/Δt

Q = (1/R) × Δφ/Δt

Q21. The total charge, induced in a conducting loop when it is moved in magnetic field depends on Source: orcusprep.in

AIPMT 1992

easy

the total change in magnetic flux

the rate of change of magnetic flux

initial magnetic flux only

final magnetic flux only

Q22. In which of the following devices, the eddy current effect is not used? Source: orcusprep.in

NEET 2019

easy

electric heater

induction furnace

magnetic braking in train

electromagnet

Q23. Eddy currents are produced when Source: orcusprep.in

AIPMT 1988

easy

a metal is kept in varying magnetic field

a metal is kept in steady magnetic field

a circular coil is placed in a magnetic field

current is passed through a circular coil

Q24. The magnetic potential energy stored in a certain inductor is 25 mJ, when the current in the inductor is 60 mA. This inductor is of inductance Source: orcusprep.in

NEET 2018

medium

13.89 H

0.138 H

138.88 H

1.389 H

Q25. A current of 2.5 A flows through a coil of inductance 5 H. The magnetic flux linked with the coil is Source: orcusprep.in

NEET 2013

easy

12.5 Wb

0.5 Wb

zero

2 Wb

Q26. The current (I) in the inductance is varying with time according to the plot shown in figure. Which one of the following is the correct variation of voltage with time in the coil? Source: orcusprep.in

AIPMT 2012

hard

Voltage is constant positive, then constant negative

Voltage is constant throughout

Voltage varies linearly

Voltage is zero throughout

Q27. The current i in a coil varies with time as shown in the figure. The variation of induced emf with time would be Source: orcusprep.in

AIPMT 2011

hard

emf is zero, then constant negative, then zero

emf is constant positive throughout

emf varies sinusoidally

emf is constant negative throughout

Q28. A long solenoid has 500 turns. When a current of 2 ampere is passed through it, the resulting magnetic flux linked with each turn of the solenoid is 4 × 10⁻³ Wb. The self-inductance of the solenoid is Source: orcusprep.in

AIPMT 2008

medium

1.0 henry

4.0 henry

2.5 henry

2.0 henry

Q29. Two coils of self inductance 2 mH and 8 mH are placed so close together that the effective flux in one coil is completely linked with the other. The mutual inductance between these coils is Source: orcusprep.in

AIPMT 2006

medium

4 mH

16 mH

10 mH

6 mH

Q30. For a coil having L = 2 mH, current flow through it is I = t²e⁻ᵗ then, the time at which emf becomes zero Source: orcusprep.in

AIPMT 2001

hard

2 sec

1 sec

4 sec

3 sec

Q31. Two coils have a mutual inductance 0.005 H. The current changes in the first coil according to equation I = I₀ sinωt, where I₀ = 10 A and ω = 100π rad/sec. The maximum value of e.m.f. in the second coil is Source: orcusprep.in

AIPMT 1998

medium

5π V

π V

2π V

4π V

Q32. If N is the number of turns in a coil, the value of self inductance varies as Source: orcusprep.in

AIPMT 1993

easy

N²

N⁰

N

N⁻²

Q33. What is the self-inductance of a coil which produces 5 V when the current changes from 3 ampere to 2 ampere in one millisecond? Source: orcusprep.in

AIPMT 1993

medium

5 mH

5000 H

5 H

50 H

Q34. If the number of turns per unit length of a coil of solenoid is doubled, the self-inductance of the solenoid will Source: orcusprep.in

AIPMT 1991

easy

become four times

remain unchanged

be halved

be doubled

Q35. A 100 millihenry coil carries a current of 1A. Energy stored in its magnetic field is Source: orcusprep.in

AIPMT 1991

easy

0.05 J

0.5 J

1 J

0.1 J

Q36. The current in self inductance L = 40 mH is to be increased uniformly from 1 amp to 11 amp in 4 milliseconds. The e.m.f. induced in inductor during process is Source: orcusprep.in

AIPMT 1990

medium

100 V

0.4 V

4.0 V

440 V

Q37. An inductor may store energy in Source: orcusprep.in

AIPMT 1990

easy

its magnetic field

its electric field

its coils

both in electric and magnetic fields

Q38. A wire loop is rotated in a magnetic field. The frequency of change of direction of the induced e.m.f. is Source: orcusprep.in

NEET 2013

easy

twice per revolution

four times per revolution

six times per revolution

once per revolution

Q39. In a region of magnetic induction B = 10⁻² tesla, a circular coil of radius 30 cm and resistance π² ohm is rotated about an axis which is perpendicular to the direction of B and which forms a diameter of the coil. If the coil rotates at 200 rpm the amplitude of the alternating current induced in the coil is Source: orcusprep.in

AIPMT 1988

hard

6 mA

4π² mA

30 mA

200 mA

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Physics - Electromagnetic Induction-PYQ

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Physics - Electromagnetic Induction-PYQ

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