JEE Main Previous Year Questions (2025): Magnetism and Matter

 Page 1


JEE Main Previous Year 
Questions (2025): Magnetism 
and Matter 
Q1: Match List - I with List - II. 
List - I List - II 
(A) Magnetic induction (I) Ampere meter  
?? 
(B) Magnetic intensity (II) Weber 
(C) Magnetic flux (III) Gauss 
(D) Magnetic moment (IV) Ampere meter 
Choose the correct answer from the options given below: 
JEE Main 2025 (Online) 29th January Evening Shift 
Options: 
A. (A)-(III), (B)-(IV), (C)-(II), (D)-(I) 
B. (A)-(III), (B)-(II), (C)-(I), (D)-(IV) 
C. (A)-(III), (B)-(IV), (C)-(I), (D)-(II) 
D. (A)-(I), (B)-(II), (C)-(III), (D)-(IV) 
Ans: A 
Solution: 
(A) The unit "gauss" is used to measure magnetic induction, also known as magnetic flux 
density, within the CGS system of units. 
?? =
?? ?? =
max well 
?? ?? 2
= gauss (CGS) 
(B) Magnetic intensity ( H ) is defined as the product of the number of turns per unit length in a 
coil ( n ) and the current that it carries (I). 
i.e. ?? = ???? =
?? ?? ?? 
Unit : A/m or Am
-1
 
(C) Magnetic flux, ?? = ???? 
unit : weber 
(D) Magnetic moment (M) : magnetic moment of a current loop, ?? = ?????? 
where, N = number of turns 
I = current 
A = Area 
So, unit = Am
2
 
Hence, option A is correct. 
Page 2


JEE Main Previous Year 
Questions (2025): Magnetism 
and Matter 
Q1: Match List - I with List - II. 
List - I List - II 
(A) Magnetic induction (I) Ampere meter  
?? 
(B) Magnetic intensity (II) Weber 
(C) Magnetic flux (III) Gauss 
(D) Magnetic moment (IV) Ampere meter 
Choose the correct answer from the options given below: 
JEE Main 2025 (Online) 29th January Evening Shift 
Options: 
A. (A)-(III), (B)-(IV), (C)-(II), (D)-(I) 
B. (A)-(III), (B)-(II), (C)-(I), (D)-(IV) 
C. (A)-(III), (B)-(IV), (C)-(I), (D)-(II) 
D. (A)-(I), (B)-(II), (C)-(III), (D)-(IV) 
Ans: A 
Solution: 
(A) The unit "gauss" is used to measure magnetic induction, also known as magnetic flux 
density, within the CGS system of units. 
?? =
?? ?? =
max well 
?? ?? 2
= gauss (CGS) 
(B) Magnetic intensity ( H ) is defined as the product of the number of turns per unit length in a 
coil ( n ) and the current that it carries (I). 
i.e. ?? = ???? =
?? ?? ?? 
Unit : A/m or Am
-1
 
(C) Magnetic flux, ?? = ???? 
unit : weber 
(D) Magnetic moment (M) : magnetic moment of a current loop, ?? = ?????? 
where, N = number of turns 
I = current 
A = Area 
So, unit = Am
2
 
Hence, option A is correct. 
Q2: The relationship between the magnetic susceptibility ( ?? ) and the magnetic 
permeability ( ?? ) is given by : 
( ?? ?? is the permeability of free space and ?? ?? is relative permeability) 
JEE Main 2025 (Online) 2nd April Morning Shift 
Options: 
A. ?? =
?? ?? 0
- 1 
B. ?? =
?? r
?? 0
+ 1 
C. ?? = ?? ?? + 1 
D. ?? = 1 -
?? ?? 0
 
Ans: A 
Solution: 
The relationship between magnetic susceptibility ( ?? ) and magnetic permeability ( ?? ) is 
expressed as follows: 
Relative Permeability ( ?? ?? ): This is defined as the ratio of the permeability of a material ( ?? ) to 
the permeability of free space ( ?? 0
 ). 
?? = ?? 0
?? ?? ? ?? ?? =
?? ?? 0
 
Magnetic Susceptibility ( ?? ): This relates to relative permeability as follows: 
?? ?? = 1 + ?? ? ?? = ?? ?? - 1 
Substituting the expression for ?? ?? from above: 
?? = (
?? ?? 0
- 1) 
Thus, the equation shows how magnetic susceptibility is derived from the magnetic permeability 
relative to free space. 
Q3: A magnetic dipole experiences a torque of ???? v?? ?? ?? when placed in uniform 
magnetic field in such a way that dipole moment makes angle of ????
°
 with magnetic 
field. The potential energy of the dipole is 
JEE Main 2025 (Online) 3rd April Evening Shift 
Options: 
A. -40v3 J 
B. -80 J 
C. 80 J 
D. -60 J 
Page 3


JEE Main Previous Year 
Questions (2025): Magnetism 
and Matter 
Q1: Match List - I with List - II. 
List - I List - II 
(A) Magnetic induction (I) Ampere meter  
?? 
(B) Magnetic intensity (II) Weber 
(C) Magnetic flux (III) Gauss 
(D) Magnetic moment (IV) Ampere meter 
Choose the correct answer from the options given below: 
JEE Main 2025 (Online) 29th January Evening Shift 
Options: 
A. (A)-(III), (B)-(IV), (C)-(II), (D)-(I) 
B. (A)-(III), (B)-(II), (C)-(I), (D)-(IV) 
C. (A)-(III), (B)-(IV), (C)-(I), (D)-(II) 
D. (A)-(I), (B)-(II), (C)-(III), (D)-(IV) 
Ans: A 
Solution: 
(A) The unit "gauss" is used to measure magnetic induction, also known as magnetic flux 
density, within the CGS system of units. 
?? =
?? ?? =
max well 
?? ?? 2
= gauss (CGS) 
(B) Magnetic intensity ( H ) is defined as the product of the number of turns per unit length in a 
coil ( n ) and the current that it carries (I). 
i.e. ?? = ???? =
?? ?? ?? 
Unit : A/m or Am
-1
 
(C) Magnetic flux, ?? = ???? 
unit : weber 
(D) Magnetic moment (M) : magnetic moment of a current loop, ?? = ?????? 
where, N = number of turns 
I = current 
A = Area 
So, unit = Am
2
 
Hence, option A is correct. 
Q2: The relationship between the magnetic susceptibility ( ?? ) and the magnetic 
permeability ( ?? ) is given by : 
( ?? ?? is the permeability of free space and ?? ?? is relative permeability) 
JEE Main 2025 (Online) 2nd April Morning Shift 
Options: 
A. ?? =
?? ?? 0
- 1 
B. ?? =
?? r
?? 0
+ 1 
C. ?? = ?? ?? + 1 
D. ?? = 1 -
?? ?? 0
 
Ans: A 
Solution: 
The relationship between magnetic susceptibility ( ?? ) and magnetic permeability ( ?? ) is 
expressed as follows: 
Relative Permeability ( ?? ?? ): This is defined as the ratio of the permeability of a material ( ?? ) to 
the permeability of free space ( ?? 0
 ). 
?? = ?? 0
?? ?? ? ?? ?? =
?? ?? 0
 
Magnetic Susceptibility ( ?? ): This relates to relative permeability as follows: 
?? ?? = 1 + ?? ? ?? = ?? ?? - 1 
Substituting the expression for ?? ?? from above: 
?? = (
?? ?? 0
- 1) 
Thus, the equation shows how magnetic susceptibility is derived from the magnetic permeability 
relative to free space. 
Q3: A magnetic dipole experiences a torque of ???? v?? ?? ?? when placed in uniform 
magnetic field in such a way that dipole moment makes angle of ????
°
 with magnetic 
field. The potential energy of the dipole is 
JEE Main 2025 (Online) 3rd April Evening Shift 
Options: 
A. -40v3 J 
B. -80 J 
C. 80 J 
D. -60 J 
Ans: B 
Solution: 
To determine the potential energy of a magnetic dipole in a uniform magnetic field, we start 
with the torque equation: 
?? = ?? × ?? = ???? sin 60
°
 
Given that ?? = 80v3 N m and sin 60
°
=
v3
2
, we can equate and solve for ???? : 
????
v3
2
= 80v3 
Solving for ???? , we find: 
???? = 160 
The potential energy ?? of the dipole in the magnetic field is given by: 
?? = -?? · ?? = -???? cos 60
°
 
Substituting in cos 60
°
=
1
2
, we calculate: 
?? = -160 ×
1
2
= -80 J 
Thus, the potential energy of the dipole is -80 J . 
Q4: The percentage increase in magnetic field (?? ) when space within a current 
carrying solenoid is filled with magnesium (magnetic susceptibility ?? ????
= ?? . ?? ×
????
-?? ) is : 
JEE Main 2025 (Online) 7th April Morning Shift 
Options: 
A. 
5
3
× 10
-5
% 
B. 
5
6
× 10
-4
% 
C. 
5
6
× 10
-5
% 
D. 
6
5
× 10
-3
% 
Ans: D 
Solution: 
The percentage change in the magnetic field (B) when the space within a current-carrying 
solenoid is filled with magnesium is calculated as follows: 
We start by using the formula for percentage change in the magnetic field: 
% change in ?? =
?? new 
-?? old 
?? old 
× 100% 
Substituting the expressions for the magnetic field, we have: 
=
?????? - ?? 0
????
?? 0
????
× 100% =
?? - ?? 0
?? 0
× 100% 
Where: 
?? is the permeability of the material inserted (here, magnesium). 
?? 0
 is the permeability of free space. 
?? is the number of turns per unit length of the solenoid. 
?? is the current through the solenoid. 
Given that the relationship between the permeability of the medium ( ?? ) and relative 
Page 4


JEE Main Previous Year 
Questions (2025): Magnetism 
and Matter 
Q1: Match List - I with List - II. 
List - I List - II 
(A) Magnetic induction (I) Ampere meter  
?? 
(B) Magnetic intensity (II) Weber 
(C) Magnetic flux (III) Gauss 
(D) Magnetic moment (IV) Ampere meter 
Choose the correct answer from the options given below: 
JEE Main 2025 (Online) 29th January Evening Shift 
Options: 
A. (A)-(III), (B)-(IV), (C)-(II), (D)-(I) 
B. (A)-(III), (B)-(II), (C)-(I), (D)-(IV) 
C. (A)-(III), (B)-(IV), (C)-(I), (D)-(II) 
D. (A)-(I), (B)-(II), (C)-(III), (D)-(IV) 
Ans: A 
Solution: 
(A) The unit "gauss" is used to measure magnetic induction, also known as magnetic flux 
density, within the CGS system of units. 
?? =
?? ?? =
max well 
?? ?? 2
= gauss (CGS) 
(B) Magnetic intensity ( H ) is defined as the product of the number of turns per unit length in a 
coil ( n ) and the current that it carries (I). 
i.e. ?? = ???? =
?? ?? ?? 
Unit : A/m or Am
-1
 
(C) Magnetic flux, ?? = ???? 
unit : weber 
(D) Magnetic moment (M) : magnetic moment of a current loop, ?? = ?????? 
where, N = number of turns 
I = current 
A = Area 
So, unit = Am
2
 
Hence, option A is correct. 
Q2: The relationship between the magnetic susceptibility ( ?? ) and the magnetic 
permeability ( ?? ) is given by : 
( ?? ?? is the permeability of free space and ?? ?? is relative permeability) 
JEE Main 2025 (Online) 2nd April Morning Shift 
Options: 
A. ?? =
?? ?? 0
- 1 
B. ?? =
?? r
?? 0
+ 1 
C. ?? = ?? ?? + 1 
D. ?? = 1 -
?? ?? 0
 
Ans: A 
Solution: 
The relationship between magnetic susceptibility ( ?? ) and magnetic permeability ( ?? ) is 
expressed as follows: 
Relative Permeability ( ?? ?? ): This is defined as the ratio of the permeability of a material ( ?? ) to 
the permeability of free space ( ?? 0
 ). 
?? = ?? 0
?? ?? ? ?? ?? =
?? ?? 0
 
Magnetic Susceptibility ( ?? ): This relates to relative permeability as follows: 
?? ?? = 1 + ?? ? ?? = ?? ?? - 1 
Substituting the expression for ?? ?? from above: 
?? = (
?? ?? 0
- 1) 
Thus, the equation shows how magnetic susceptibility is derived from the magnetic permeability 
relative to free space. 
Q3: A magnetic dipole experiences a torque of ???? v?? ?? ?? when placed in uniform 
magnetic field in such a way that dipole moment makes angle of ????
°
 with magnetic 
field. The potential energy of the dipole is 
JEE Main 2025 (Online) 3rd April Evening Shift 
Options: 
A. -40v3 J 
B. -80 J 
C. 80 J 
D. -60 J 
Ans: B 
Solution: 
To determine the potential energy of a magnetic dipole in a uniform magnetic field, we start 
with the torque equation: 
?? = ?? × ?? = ???? sin 60
°
 
Given that ?? = 80v3 N m and sin 60
°
=
v3
2
, we can equate and solve for ???? : 
????
v3
2
= 80v3 
Solving for ???? , we find: 
???? = 160 
The potential energy ?? of the dipole in the magnetic field is given by: 
?? = -?? · ?? = -???? cos 60
°
 
Substituting in cos 60
°
=
1
2
, we calculate: 
?? = -160 ×
1
2
= -80 J 
Thus, the potential energy of the dipole is -80 J . 
Q4: The percentage increase in magnetic field (?? ) when space within a current 
carrying solenoid is filled with magnesium (magnetic susceptibility ?? ????
= ?? . ?? ×
????
-?? ) is : 
JEE Main 2025 (Online) 7th April Morning Shift 
Options: 
A. 
5
3
× 10
-5
% 
B. 
5
6
× 10
-4
% 
C. 
5
6
× 10
-5
% 
D. 
6
5
× 10
-3
% 
Ans: D 
Solution: 
The percentage change in the magnetic field (B) when the space within a current-carrying 
solenoid is filled with magnesium is calculated as follows: 
We start by using the formula for percentage change in the magnetic field: 
% change in ?? =
?? new 
-?? old 
?? old 
× 100% 
Substituting the expressions for the magnetic field, we have: 
=
?????? - ?? 0
????
?? 0
????
× 100% =
?? - ?? 0
?? 0
× 100% 
Where: 
?? is the permeability of the material inserted (here, magnesium). 
?? 0
 is the permeability of free space. 
?? is the number of turns per unit length of the solenoid. 
?? is the current through the solenoid. 
Given that the relationship between the permeability of the medium ( ?? ) and relative 
permeability ( ?? ?? ) is: 
?? = ?? 0
?? ?? 
We can simplify this to: 
=
?? 0
?? ?? - ?? 0
?? 0
× 100% 
Which reduces to: 
= (?? ?? - 1) × 100% 
The relative permeability ?? ?? is equal to 1 + ?? , where ?? is the magnetic susceptibility. Thus, we 
have: 
= ?? × 100% 
When magnesium is used, with a magnetic susceptibility ?? Mg
= 1.2 × 10
-5
, the calculation 
becomes: 
= 1.2 × 10
-5
× 100% = 1.2 × 10
-3
% 
Therefore, the percentage increase in the magnetic field when the solenoid is filled with 
magnesium is 1.2 × 10
-3
%. 
Q5: Given below are two statements: one is labelled as Assertion (A) and the other is 
labelled as Reason (R). 
Assertion (A): Magnetic monopoles do not exist. 
Reason (R): Magnetic field lines are continuous and form closed loops. 
In the light of the above statements, choose the most appropriate answer from the 
options given below: 
JEE Main 2025 (Online) 7th April Evening Shift 
Options: 
A. Both (A) and (R) are correct and (R) is the correct explanation of (A) 
B. (A) is not correct but (R) is correct 
C. (A) is correct but (R) is not correct 
D. Both (A) and (R) are correct but (R) is not the correct explanation of (A) 
Ans: A 
Solution: 
The assertion states that magnetic monopoles do not exist. This is consistent with current 
experimental findings and the standard formulation of Maxwell's equations. 
The reason provided is that magnetic field lines are continuous and form closed loops. This is 
mathematically expressed by the Maxwell equation: 
? · ?? = 0 
This equation tells us that there are no "sources" or "sinks" of magnetic fields (unlike electric 
fields, which can originate or terminate at charges). In other words, magnetic field lines neither 
begin nor end; they loop continuously. 
Since the fact that the magnetic field lines form closed loops is a direct consequence of the 
absence of isolated magnetic charges (monopoles), the reason correctly explains the assertion. 
Thus, both (A) and (R) are correct, and (R) is the correct explanation of (A). 
The most appropriate answer is Option A. 
 
Page 5


JEE Main Previous Year 
Questions (2025): Magnetism 
and Matter 
Q1: Match List - I with List - II. 
List - I List - II 
(A) Magnetic induction (I) Ampere meter  
?? 
(B) Magnetic intensity (II) Weber 
(C) Magnetic flux (III) Gauss 
(D) Magnetic moment (IV) Ampere meter 
Choose the correct answer from the options given below: 
JEE Main 2025 (Online) 29th January Evening Shift 
Options: 
A. (A)-(III), (B)-(IV), (C)-(II), (D)-(I) 
B. (A)-(III), (B)-(II), (C)-(I), (D)-(IV) 
C. (A)-(III), (B)-(IV), (C)-(I), (D)-(II) 
D. (A)-(I), (B)-(II), (C)-(III), (D)-(IV) 
Ans: A 
Solution: 
(A) The unit "gauss" is used to measure magnetic induction, also known as magnetic flux 
density, within the CGS system of units. 
?? =
?? ?? =
max well 
?? ?? 2
= gauss (CGS) 
(B) Magnetic intensity ( H ) is defined as the product of the number of turns per unit length in a 
coil ( n ) and the current that it carries (I). 
i.e. ?? = ???? =
?? ?? ?? 
Unit : A/m or Am
-1
 
(C) Magnetic flux, ?? = ???? 
unit : weber 
(D) Magnetic moment (M) : magnetic moment of a current loop, ?? = ?????? 
where, N = number of turns 
I = current 
A = Area 
So, unit = Am
2
 
Hence, option A is correct. 
Q2: The relationship between the magnetic susceptibility ( ?? ) and the magnetic 
permeability ( ?? ) is given by : 
( ?? ?? is the permeability of free space and ?? ?? is relative permeability) 
JEE Main 2025 (Online) 2nd April Morning Shift 
Options: 
A. ?? =
?? ?? 0
- 1 
B. ?? =
?? r
?? 0
+ 1 
C. ?? = ?? ?? + 1 
D. ?? = 1 -
?? ?? 0
 
Ans: A 
Solution: 
The relationship between magnetic susceptibility ( ?? ) and magnetic permeability ( ?? ) is 
expressed as follows: 
Relative Permeability ( ?? ?? ): This is defined as the ratio of the permeability of a material ( ?? ) to 
the permeability of free space ( ?? 0
 ). 
?? = ?? 0
?? ?? ? ?? ?? =
?? ?? 0
 
Magnetic Susceptibility ( ?? ): This relates to relative permeability as follows: 
?? ?? = 1 + ?? ? ?? = ?? ?? - 1 
Substituting the expression for ?? ?? from above: 
?? = (
?? ?? 0
- 1) 
Thus, the equation shows how magnetic susceptibility is derived from the magnetic permeability 
relative to free space. 
Q3: A magnetic dipole experiences a torque of ???? v?? ?? ?? when placed in uniform 
magnetic field in such a way that dipole moment makes angle of ????
°
 with magnetic 
field. The potential energy of the dipole is 
JEE Main 2025 (Online) 3rd April Evening Shift 
Options: 
A. -40v3 J 
B. -80 J 
C. 80 J 
D. -60 J 
Ans: B 
Solution: 
To determine the potential energy of a magnetic dipole in a uniform magnetic field, we start 
with the torque equation: 
?? = ?? × ?? = ???? sin 60
°
 
Given that ?? = 80v3 N m and sin 60
°
=
v3
2
, we can equate and solve for ???? : 
????
v3
2
= 80v3 
Solving for ???? , we find: 
???? = 160 
The potential energy ?? of the dipole in the magnetic field is given by: 
?? = -?? · ?? = -???? cos 60
°
 
Substituting in cos 60
°
=
1
2
, we calculate: 
?? = -160 ×
1
2
= -80 J 
Thus, the potential energy of the dipole is -80 J . 
Q4: The percentage increase in magnetic field (?? ) when space within a current 
carrying solenoid is filled with magnesium (magnetic susceptibility ?? ????
= ?? . ?? ×
????
-?? ) is : 
JEE Main 2025 (Online) 7th April Morning Shift 
Options: 
A. 
5
3
× 10
-5
% 
B. 
5
6
× 10
-4
% 
C. 
5
6
× 10
-5
% 
D. 
6
5
× 10
-3
% 
Ans: D 
Solution: 
The percentage change in the magnetic field (B) when the space within a current-carrying 
solenoid is filled with magnesium is calculated as follows: 
We start by using the formula for percentage change in the magnetic field: 
% change in ?? =
?? new 
-?? old 
?? old 
× 100% 
Substituting the expressions for the magnetic field, we have: 
=
?????? - ?? 0
????
?? 0
????
× 100% =
?? - ?? 0
?? 0
× 100% 
Where: 
?? is the permeability of the material inserted (here, magnesium). 
?? 0
 is the permeability of free space. 
?? is the number of turns per unit length of the solenoid. 
?? is the current through the solenoid. 
Given that the relationship between the permeability of the medium ( ?? ) and relative 
permeability ( ?? ?? ) is: 
?? = ?? 0
?? ?? 
We can simplify this to: 
=
?? 0
?? ?? - ?? 0
?? 0
× 100% 
Which reduces to: 
= (?? ?? - 1) × 100% 
The relative permeability ?? ?? is equal to 1 + ?? , where ?? is the magnetic susceptibility. Thus, we 
have: 
= ?? × 100% 
When magnesium is used, with a magnetic susceptibility ?? Mg
= 1.2 × 10
-5
, the calculation 
becomes: 
= 1.2 × 10
-5
× 100% = 1.2 × 10
-3
% 
Therefore, the percentage increase in the magnetic field when the solenoid is filled with 
magnesium is 1.2 × 10
-3
%. 
Q5: Given below are two statements: one is labelled as Assertion (A) and the other is 
labelled as Reason (R). 
Assertion (A): Magnetic monopoles do not exist. 
Reason (R): Magnetic field lines are continuous and form closed loops. 
In the light of the above statements, choose the most appropriate answer from the 
options given below: 
JEE Main 2025 (Online) 7th April Evening Shift 
Options: 
A. Both (A) and (R) are correct and (R) is the correct explanation of (A) 
B. (A) is not correct but (R) is correct 
C. (A) is correct but (R) is not correct 
D. Both (A) and (R) are correct but (R) is not the correct explanation of (A) 
Ans: A 
Solution: 
The assertion states that magnetic monopoles do not exist. This is consistent with current 
experimental findings and the standard formulation of Maxwell's equations. 
The reason provided is that magnetic field lines are continuous and form closed loops. This is 
mathematically expressed by the Maxwell equation: 
? · ?? = 0 
This equation tells us that there are no "sources" or "sinks" of magnetic fields (unlike electric 
fields, which can originate or terminate at charges). In other words, magnetic field lines neither 
begin nor end; they loop continuously. 
Since the fact that the magnetic field lines form closed loops is a direct consequence of the 
absence of isolated magnetic charges (monopoles), the reason correctly explains the assertion. 
Thus, both (A) and (R) are correct, and (R) is the correct explanation of (A). 
The most appropriate answer is Option A. 
 
 
 
 
Q6:  
 
A bar magnet has total length ?? ?? = ???? units and the field point P is at a distance ?? =
???? units from the centre of the magnet. If the relative uncertainty of length 
measurement is ?? %, then uncertainty of the magnetic field at point ?? is : 
JEE Main 2025 (Online) 28th January Evening Shift  
(MCQ (More than One Correct Answer) 
A. 10% 
B. 5% 
C. 3% 
D. 4% 
Ans: C, D 
Explanation 
To determine the uncertainty of the magnetic field at point P , we consider two approaches: 
Without considering uncertainty in length l : 
The magnetic field ?? at point P is given by: 
?? =
?? 0
4?? ?? ?? 3
 
Where ?? is inversely proportional to ?? 3
 :