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PHXII05:MAGNETISM and MATTER

360571 Assertion :
Magnetism is relativistic.
Reason :
When we move along with the charge (like electron with $10^{7} m / s$ ) so that there is no motion relative to us, we find no magnetic field associated with the charge.

1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.

2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.

3 Assertion is correct but Reason is incorrect.

4 Assertion is incorrect but reason is correct.

Explanation:

$c = \frac{E_{max}}{B_{max}} = 3 \times 10^{8} m / s$
Magnetism, as described by the theory of special relativity, is indeed relativistic. Note $10^{7}$ is of order $10^{8}$ . When an observer moves along with a charge so that there is no relative motion, they perceive no magnetic field associated with the charge. So correct option is (1).

PHXII05:MAGNETISM and MATTER

360572 Assertion :
A disc-shaped magnet is levitated above a superconducting material that has been cooled by liquid nitrogen.
Reason :
Superconductors repel a magnet.

1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.

2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.

3 Assertion is correct but Reason is incorrect.

4 Assertion is incorrect but reason is correct.

Explanation:

Super conductors are diamagnetic below $T_{C}$ (Here $T_{C}$ means temperature at which normal conductor becomes super conductor). When superconductors reach their critical temperature $(T_{C})$ , the Meissner effect expels magnetic fields, causing magnetic repulsion. This repulsion, seen when a magnet hoveres above a cooled superconductor, is due to the induced magnetic field opposing the applied field. So correct option is (1).

PHXII05:MAGNETISM and MATTER

360573 A toroid of $n$ turns, mean radius $R$ and crosssectional radius a carries current $I$ . It is placed on a horizontal table taken as $x - y$ plane. Its magnetic moment $M$

1 Is non-zero and points in the

z

-direction by symmetry

2 Points along the axis of the toriod

(M \neq 0)

3 Is pointing radially outwards

4 Is zero

Explanation:

The magnetic moment of each loop of the toroid can be treated as small vector. This vector will be present perpendicular to the loop. The net moment is the sum of vectors which form a closed circle
${\bar{M}}_{net} = 0$

NCERT Exemplar

PHXII05:MAGNETISM and MATTER

360574 Assertion :
To protect any instrument from external magnetic field, it is put inside an iron body.
Reason :
Iron on its own is a magnetic substance.

1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.

2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.

3 Assertion is correct but Reason is incorrect.

4 Assertion is incorrect but reason is correct.

PHXII05:MAGNETISM and MATTER

360575 The mathematical equation for magnetic field lines of force is

1

\nabla \cdot B = 0

2

\nabla \cdot B \neq 0

3

\nabla \cdot B > 0

4

\nabla \cdot B < 0

Explanation:

The divergence of magnetic field is always zero, $i . e . \nabla \cdot B = 0.$

PHXII05:MAGNETISM and MATTER

360571 Assertion :
Magnetism is relativistic.
Reason :
When we move along with the charge (like electron with $10^{7} m / s$ ) so that there is no motion relative to us, we find no magnetic field associated with the charge.

1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.

2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.

3 Assertion is correct but Reason is incorrect.

4 Assertion is incorrect but reason is correct.

Explanation:

$c = \frac{E_{max}}{B_{max}} = 3 \times 10^{8} m / s$
Magnetism, as described by the theory of special relativity, is indeed relativistic. Note $10^{7}$ is of order $10^{8}$ . When an observer moves along with a charge so that there is no relative motion, they perceive no magnetic field associated with the charge. So correct option is (1).

PHXII05:MAGNETISM and MATTER

360572 Assertion :
A disc-shaped magnet is levitated above a superconducting material that has been cooled by liquid nitrogen.
Reason :
Superconductors repel a magnet.

1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.

2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.

3 Assertion is correct but Reason is incorrect.

4 Assertion is incorrect but reason is correct.

Explanation:

Super conductors are diamagnetic below $T_{C}$ (Here $T_{C}$ means temperature at which normal conductor becomes super conductor). When superconductors reach their critical temperature $(T_{C})$ , the Meissner effect expels magnetic fields, causing magnetic repulsion. This repulsion, seen when a magnet hoveres above a cooled superconductor, is due to the induced magnetic field opposing the applied field. So correct option is (1).

PHXII05:MAGNETISM and MATTER

360573 A toroid of $n$ turns, mean radius $R$ and crosssectional radius a carries current $I$ . It is placed on a horizontal table taken as $x - y$ plane. Its magnetic moment $M$

1 Is non-zero and points in the

z

-direction by symmetry

2 Points along the axis of the toriod

(M \neq 0)

3 Is pointing radially outwards

4 Is zero

Explanation:

The magnetic moment of each loop of the toroid can be treated as small vector. This vector will be present perpendicular to the loop. The net moment is the sum of vectors which form a closed circle
${\bar{M}}_{net} = 0$

NCERT Exemplar

PHXII05:MAGNETISM and MATTER

360574 Assertion :
To protect any instrument from external magnetic field, it is put inside an iron body.
Reason :
Iron on its own is a magnetic substance.

1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.

2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.

3 Assertion is correct but Reason is incorrect.

4 Assertion is incorrect but reason is correct.

PHXII05:MAGNETISM and MATTER

360575 The mathematical equation for magnetic field lines of force is

1

\nabla \cdot B = 0

2

\nabla \cdot B \neq 0

3

\nabla \cdot B > 0

4

\nabla \cdot B < 0

Explanation:

The divergence of magnetic field is always zero, $i . e . \nabla \cdot B = 0.$

PHXII05:MAGNETISM and MATTER

360571 Assertion :
Magnetism is relativistic.
Reason :
When we move along with the charge (like electron with $10^{7} m / s$ ) so that there is no motion relative to us, we find no magnetic field associated with the charge.

1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.

2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.

3 Assertion is correct but Reason is incorrect.

4 Assertion is incorrect but reason is correct.

Explanation:

$c = \frac{E_{max}}{B_{max}} = 3 \times 10^{8} m / s$
Magnetism, as described by the theory of special relativity, is indeed relativistic. Note $10^{7}$ is of order $10^{8}$ . When an observer moves along with a charge so that there is no relative motion, they perceive no magnetic field associated with the charge. So correct option is (1).

PHXII05:MAGNETISM and MATTER

360572 Assertion :
A disc-shaped magnet is levitated above a superconducting material that has been cooled by liquid nitrogen.
Reason :
Superconductors repel a magnet.

1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.

2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.

3 Assertion is correct but Reason is incorrect.

4 Assertion is incorrect but reason is correct.

Explanation:

Super conductors are diamagnetic below $T_{C}$ (Here $T_{C}$ means temperature at which normal conductor becomes super conductor). When superconductors reach their critical temperature $(T_{C})$ , the Meissner effect expels magnetic fields, causing magnetic repulsion. This repulsion, seen when a magnet hoveres above a cooled superconductor, is due to the induced magnetic field opposing the applied field. So correct option is (1).

PHXII05:MAGNETISM and MATTER

360573 A toroid of $n$ turns, mean radius $R$ and crosssectional radius a carries current $I$ . It is placed on a horizontal table taken as $x - y$ plane. Its magnetic moment $M$

1 Is non-zero and points in the

z

-direction by symmetry

2 Points along the axis of the toriod

(M \neq 0)

3 Is pointing radially outwards

4 Is zero

Explanation:

The magnetic moment of each loop of the toroid can be treated as small vector. This vector will be present perpendicular to the loop. The net moment is the sum of vectors which form a closed circle
${\bar{M}}_{net} = 0$

NCERT Exemplar

PHXII05:MAGNETISM and MATTER

360574 Assertion :
To protect any instrument from external magnetic field, it is put inside an iron body.
Reason :
Iron on its own is a magnetic substance.

1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.

2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.

3 Assertion is correct but Reason is incorrect.

4 Assertion is incorrect but reason is correct.

PHXII05:MAGNETISM and MATTER

360575 The mathematical equation for magnetic field lines of force is

1

\nabla \cdot B = 0

2

\nabla \cdot B \neq 0

3

\nabla \cdot B > 0

4

\nabla \cdot B < 0

Explanation:

The divergence of magnetic field is always zero, $i . e . \nabla \cdot B = 0.$

PHXII05:MAGNETISM and MATTER

360571 Assertion :
Magnetism is relativistic.
Reason :
When we move along with the charge (like electron with $10^{7} m / s$ ) so that there is no motion relative to us, we find no magnetic field associated with the charge.

1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.

2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.

3 Assertion is correct but Reason is incorrect.

4 Assertion is incorrect but reason is correct.

Explanation:

$c = \frac{E_{max}}{B_{max}} = 3 \times 10^{8} m / s$
Magnetism, as described by the theory of special relativity, is indeed relativistic. Note $10^{7}$ is of order $10^{8}$ . When an observer moves along with a charge so that there is no relative motion, they perceive no magnetic field associated with the charge. So correct option is (1).

PHXII05:MAGNETISM and MATTER

360572 Assertion :
A disc-shaped magnet is levitated above a superconducting material that has been cooled by liquid nitrogen.
Reason :
Superconductors repel a magnet.

1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.

2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.

3 Assertion is correct but Reason is incorrect.

4 Assertion is incorrect but reason is correct.

Explanation:

Super conductors are diamagnetic below $T_{C}$ (Here $T_{C}$ means temperature at which normal conductor becomes super conductor). When superconductors reach their critical temperature $(T_{C})$ , the Meissner effect expels magnetic fields, causing magnetic repulsion. This repulsion, seen when a magnet hoveres above a cooled superconductor, is due to the induced magnetic field opposing the applied field. So correct option is (1).

PHXII05:MAGNETISM and MATTER

360573 A toroid of $n$ turns, mean radius $R$ and crosssectional radius a carries current $I$ . It is placed on a horizontal table taken as $x - y$ plane. Its magnetic moment $M$

1 Is non-zero and points in the

z

-direction by symmetry

2 Points along the axis of the toriod

(M \neq 0)

3 Is pointing radially outwards

4 Is zero

Explanation:

The magnetic moment of each loop of the toroid can be treated as small vector. This vector will be present perpendicular to the loop. The net moment is the sum of vectors which form a closed circle
${\bar{M}}_{net} = 0$

NCERT Exemplar

PHXII05:MAGNETISM and MATTER

360574 Assertion :
To protect any instrument from external magnetic field, it is put inside an iron body.
Reason :
Iron on its own is a magnetic substance.

1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.

2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.

3 Assertion is correct but Reason is incorrect.

4 Assertion is incorrect but reason is correct.

PHXII05:MAGNETISM and MATTER

360575 The mathematical equation for magnetic field lines of force is

1

\nabla \cdot B = 0

2

\nabla \cdot B \neq 0

3

\nabla \cdot B > 0

4

\nabla \cdot B < 0

Explanation:

The divergence of magnetic field is always zero, $i . e . \nabla \cdot B = 0.$

PHXII05:MAGNETISM and MATTER

360571 Assertion :
Magnetism is relativistic.
Reason :
When we move along with the charge (like electron with $10^{7} m / s$ ) so that there is no motion relative to us, we find no magnetic field associated with the charge.

1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.

2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.

3 Assertion is correct but Reason is incorrect.

4 Assertion is incorrect but reason is correct.

Explanation:

$c = \frac{E_{max}}{B_{max}} = 3 \times 10^{8} m / s$
Magnetism, as described by the theory of special relativity, is indeed relativistic. Note $10^{7}$ is of order $10^{8}$ . When an observer moves along with a charge so that there is no relative motion, they perceive no magnetic field associated with the charge. So correct option is (1).

PHXII05:MAGNETISM and MATTER

360572 Assertion :
A disc-shaped magnet is levitated above a superconducting material that has been cooled by liquid nitrogen.
Reason :
Superconductors repel a magnet.

1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.

2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.

3 Assertion is correct but Reason is incorrect.

4 Assertion is incorrect but reason is correct.

Explanation:

Super conductors are diamagnetic below $T_{C}$ (Here $T_{C}$ means temperature at which normal conductor becomes super conductor). When superconductors reach their critical temperature $(T_{C})$ , the Meissner effect expels magnetic fields, causing magnetic repulsion. This repulsion, seen when a magnet hoveres above a cooled superconductor, is due to the induced magnetic field opposing the applied field. So correct option is (1).

PHXII05:MAGNETISM and MATTER

360573 A toroid of $n$ turns, mean radius $R$ and crosssectional radius a carries current $I$ . It is placed on a horizontal table taken as $x - y$ plane. Its magnetic moment $M$

1 Is non-zero and points in the

z

-direction by symmetry

2 Points along the axis of the toriod

(M \neq 0)

3 Is pointing radially outwards

4 Is zero

Explanation:

The magnetic moment of each loop of the toroid can be treated as small vector. This vector will be present perpendicular to the loop. The net moment is the sum of vectors which form a closed circle
${\bar{M}}_{net} = 0$

NCERT Exemplar

PHXII05:MAGNETISM and MATTER

360574 Assertion :
To protect any instrument from external magnetic field, it is put inside an iron body.
Reason :
Iron on its own is a magnetic substance.

1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.

2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.

3 Assertion is correct but Reason is incorrect.

4 Assertion is incorrect but reason is correct.

PHXII05:MAGNETISM and MATTER

360575 The mathematical equation for magnetic field lines of force is

1

\nabla \cdot B = 0

2

\nabla \cdot B \neq 0

3

\nabla \cdot B > 0

4

\nabla \cdot B < 0

Explanation:

The divergence of magnetic field is always zero, $i . e . \nabla \cdot B = 0.$