Quiz - physics - Magnetism and Matter-PYQ

Q1. A 250-turn rectangular coil of length 2.1 cm and width 1.25 cm carries a current of 85 mA and subjected to a magnetic field of strength 0.85 T. Work done for rotating the coil by 180° against the torque is Source: orcusprep.in

NEET 2017

medium

9.1 mJ

4.55 mJ

2.3 mJ

1.15 mJ

Q2. A bar magnet is hung by a thin cotton thread in a uniform horizontal magnetic field and is in equilibrium state. The energy required to rotate it by 60° is W. Now the torque required to keep the magnet in this new position is Source: orcusprep.in

NEET 2016

hard

$\sqrt{3}W$

$\frac{W}{\sqrt{3}}$

$\frac{3}{2}W$

$\frac{2}{3}W$

Q3. Following figures show the arrangement of bar magnets in different configurations. Each magnet has magnetic dipole moment $\vec{m}$. Which configuration has highest net magnetic dipole moment? Source: orcusprep.in

AIPMT 2014

medium

(1)

(2)

(3)

(4)

Q4. A bar magnet of length l and magnetic dipole moment M is bent in the form of an arc as shown in figure. The new magnetic dipole moment will be Source: orcusprep.in

NEET 2013

hard

$\frac{3}{\pi}M$

$\frac{2}{\pi}M$

$\frac{M}{2}$

$M$

Q5. A bar magnet of magnetic moment M is placed at right angles to a magnetic induction B. If a force F is experienced by each pole of the magnet, the length of the magnet will be Source: orcusprep.in

NEET 2013

medium

$\frac{MB}{F}$

$\frac{BF}{M}$

$\frac{MF}{B}$

$\frac{F}{MB}$

Q6. A magnetic needle suspended parallel to a magnetic field requires 3 J of work to turn it through 60°. The torque needed to maintain the needle in this position will be Source: orcusprep.in

AIPMT 2012

medium

$\sqrt{3}$ J

$2\sqrt{3}$ J

3 J

$\frac{3}{2}$ J

Q7. A short bar magnet of magnetic moment 0.4 J T⁻¹ is placed in a uniform magnetic field of 0.16 T. The magnet is in stable equilibrium when the potential energy is Source: orcusprep.in

AIPMT 2011

easy

-0.064 J

0.064 J

zero

-0.082 J

Q8. A vibration magnetometer placed in magnetic meridian has a small bar magnet. The magnet executes oscillations with a time period of 2 sec in earths horizontal magnetic field of 24 microtesla. When a horizontal field of 18 microtesla is produced opposite to the earth's field by placing a current carrying wire, the new time period of magnet will be Source: orcusprep.in

AIPMT 2010

medium

4 s

1 s

2 s

3 s

Q9. Two identical bar magnets are fixed with their centres at a distance d apart. A stationary charge Q is placed at P in between the gap of the two magnets at a distance D from the centre O as shown in the figure. The force on the charge Q is Source: orcusprep.in

AIPMT 2010

medium

zero

directed along OP

directed along PO

directed perpendicular to the plane of paper

Q10. A closely wound solenoid of 2000 turns and area of cross-section 1.5 × 10⁻⁴ m² carries a current of 2.0 A. It is suspended through its centre and perpendicular to its length, allowing it to turn in a horizontal plane in a uniform magnetic field 5 × 10⁻² tesla making an angle of 30° with the axis of the solenoid. The torque on the solenoid will be Source: orcusprep.in

AIPMT 2010

medium

1.5 × 10⁻³ N m

3 × 10⁻³ N m

1.5 × 10⁻² N m

3 × 10⁻² N m

Q11. A bar magnet having a magnetic moment of 2×10⁴ J T⁻¹ is free to rotate in a horizontal plane. A horizontal magnetic field B = 6 × 10⁻⁴ T exists in the space. The work done in taking the magnet slowly from a direction parallel to the field to a direction 60° from the field is Source: orcusprep.in

AIPMT 2009

medium

6 J

12 J

2 J

0.6 J

Q12. A bar magnet is oscillating in the Earth's magnetic field with a period T. What happens to its period and motion if its mass is quadrupled? Source: orcusprep.in

AIPMT 2003

medium

Motion remains S.H.M with time period = 2T

Motion remains simple harmonic with time period = T/2

Motion remains S.H.M with time period = 4T

Motion remains S.H.M and period remains nearly constant

Q13. Two bar magnets having same geometry with magnetic moments M and 2M, are firstly placed in such a way that their similar poles are in same side then its time period of oscillation is T₁. Now the polarity of one of the magnet is reversed then time period of oscillation is T₂, then Source: orcusprep.in

AIPMT 2002

hard

T₁ < T₂

T₁ = T₂

T₁ > T₂

T₂ = ∞

Q14. A bar magnet of magnetic moment $\vec{M}$, is placed in a magnetic field of induction $\vec{B}$. The torque exerted on it is Source: orcusprep.in

AIPMT 1999

easy

$\vec{M} × \vec{B}$

$-\vec{M} \cdot \vec{B}$

$\vec{M} \cdot \vec{B}$

$-\vec{B} × \vec{M}$

Q15. A bar magnet of magnetic moment M is cut into two parts of equal length. The magnetic moment of each part will be Source: orcusprep.in

AIPMT 1997

easy

0.5M

M

2M

zero

Q16. The work done in turning a magnet of magnetic moment M by an angle of 90° from the meridian, is n times the corresponding work done to turn it through an angle of 60°. The value of n is given by Source: orcusprep.in

AIPMT 1995

medium

2

1/2

1/4

1

Q17. At a point A on the earth's surface the angle of dip, δ = +25°. At a point B on the earth's surface the angle of dip, δ = -25°. We can interpret that Source: orcusprep.in

NEET 2019

medium

A is located in the northern hemisphere and B is located in the southern hemisphere

A and B are both located in the southern hemisphere

A and B are both located in the northern hemisphere

A is located in the southern hemisphere and B is located in the northern hemisphere

Q18. If θ₁ and θ₂ be the apparent angles of dip observed in two vertical planes at right angles to each other, then the true angle of dip θ is given by Source: orcusprep.in

NEET 2017

hard

cot²θ = cot²θ₁ + cot²θ₂

tan²θ = tan²θ₁ + tan²θ₂

cot²θ = cot²θ₁ - cot²θ₂

tan²θ = tan²θ₁ - tan²θ₂

Q19. A compass needle which is allowed to move in a horizontal plane is taken to a geomagnetic pole. It Source: orcusprep.in

AIPMT 2012

medium

will stay in any position

will become rigid showing no movement

will stay in north-south direction only

will stay in east-west direction only

Q20. Tangent galvanometer is used to measure Source: orcusprep.in

AIPMT 2001

easy

current

potential difference

resistance

charge

Q21. An iron rod of susceptibility 599 is subjected to a magnetising field of 1200 A m⁻¹. The permeability of the material of the rod is (μ₀ = 4π × 10⁻⁷ T m A⁻¹) Source: orcusprep.in

NEET 2020

medium

2.4π × 10⁻⁴ T m A⁻¹

8.0 × 10⁻⁵ T m A⁻¹

2.4π × 10⁻⁵ T m A⁻¹

2.4π × 10⁻⁷ T m A⁻¹

Q22. A thin diamagnetic rod is placed vertically between the poles of an electromagnet. When the current in the electromagnet is switched on, then the diamagnetic rod is pushed up, out of the horizontal magnetic field. Hence the rod gains gravitational potential energy. The work required to do this comes from Source: orcusprep.in

NEET 2018

medium

the current source

the magnetic field

the lattice structure of the material of the rod

the induced electric field due to the changing magnetic field

Q23. The magnetic susceptibility is negative for Source: orcusprep.in

NEET 2016

easy

diamagnetic material only

ferromagnetic material only

paramagnetic and ferromagnetic materials

paramagnetic material only

Q24. There are four light-weight-rod samples A, B, C, D separately suspended by threads. A bar magnet is slowly brought near each sample and the following observations are noted: (i) A is feebly repelled (ii) B is feebly attracted (iii) C is strongly attracted (iv) D remains unaffected. Which one of the following is true? Source: orcusprep.in

AIPMT 2011

medium

C is of a ferromagnetic material

A is of a non-magnetic material

B is of a diamagnetic material

D is of a ferromagnetic material

Q25. There are four light-weight-rod samples A, B, C, D separately suspended by threads. A bar magnet is slowly brought near each sample and the following observations are noted: (i) A is feebly repelled (ii) B is feebly attracted (iii) C is strongly attracted (iv) D remains unaffected. Which one of the following is true? Source: orcusprep.in

AIPMT 2011

medium

B is of a paramagnetic material

C is of a diamagnetic material

D is of a ferromagnetic material

A is of a non-magnetic material

Q26. The magnetic moment of a diamagnetic atom is Source: orcusprep.in

AIPMT 2010

easy

equal to zero

much greater than one

1

between zero and one

Q27. If a diamagnetic substance is brought near the north or the south pole of a bar magnet, it is Source: orcusprep.in

AIPMT 2009

easy

repelled by both the poles

repelled by the north pole and attracted by the south pole

attracted by the north pole and repelled by the south pole

attracted by both the poles

Q28. Curie temperature above which Source: orcusprep.in

AIPMT 2008

easy

ferromagnetic material becomes paramagnetic material

paramagnetic material becomes ferromagnetic material

ferromagnetic material becomes diamagnetic material

paramagnetic material becomes diamagnetic material

Q29. Nickel shows ferromagnetic property at room temperature. If the temperature is increased beyond Curie temperature, then it will show Source: orcusprep.in

AIPMT 2007

easy

paramagnetism

anti ferromagnetism

no magnetic property

diamagnetism

Q30. If the magnetic dipole moment of an atom of diamagnetic material, paramagnetic material and ferromagnetic material are denoted by μ_d, μ_p and μ_f respectively, then Source: orcusprep.in

AIPMT 2005

medium

μ_d = 0 and μ_p ≠ 0

μ_d ≠ 0 and μ_p = 0

μ_p = 0 and μ_f ≠ 0

μ_d ≠ 0 and μ_f ≠ 0

Q31. A diamagnetic material in a magnetic field moves Source: orcusprep.in

AIPMT 2003

easy

from stronger to the weaker parts of the field

from weaker to the stronger parts of the field

perpendicular to the field

in none of the above directions

Q32. According to Curie's law, the magnetic susceptibility of a substance at an absolute temperature T is proportional to Source: orcusprep.in

AIPMT 2003

easy

1/T

T

1/T²

T²

Q33. Among which the magnetic susceptibility does not depend on the temperature? Source: orcusprep.in

AIPMT 2001

easy

Diamagnetism

Paramagnetism

Ferromagnetism

Ferrite

Q34. For protecting a sensitive equipment from the external magnetic field, it should be Source: orcusprep.in

AIPMT 1998

medium

placed inside an iron can

surrounded with fine copper sheet

wrapped with insulation around it when passing current through it

placed inside an aluminium can

Q35. Electromagnets are made of soft iron because soft iron has Source: orcusprep.in

AIPMT 2010

easy

low retentivity and low coercive force

low retentivity and high coercive force

high retentivity and high coercive force

high retentivity and low coercive force

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Physics - Magnetism and Matter-PYQ

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Physics - Magnetism and Matter-PYQ

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