Friction: JEE Mains Previous Year Questions (2021-2024) | Physics for JEE Main & Advanced PDF Download

 Page 1


JEE Mains Previous Year Questions 
(2021-2024): Friction 
2024 
Q1: Consider a block and trolley system as shown in figure. If the coefficient of kinetic friction 
between the trolley and the surface is 0.04 , the acceleration of the system in ????
-?? is : 
(Consider that the string is massless and unstretchable and the pulley is also massless and 
frictionless): 
 
 
A. 1.2 
B. 4 
(C. 3 
D. 2      [JEE Main 2024 (Online) 1st February Morning Shift] 
Ans: (d) 
60 - ?? ?? = (20 + 6)?? 
60 - 200 × 0.04 = 26?? ? ?? = 2 m/s
2
 
Q2: A block of mass ?? ???? is placed on a rough inclined surface as shown in the figure. If ?? ?? ???? 
 is the force 
required to just move the block up the inclined plane and ?? ? ? 
?? is the force required to just prevent the 
block from sliding down, then the value of |?? ?? ???? 
| - |?? ?? ???? 
| is : [Use ?? = ???? ?? /?? ?? ] 
A. ?? v?? ?? 
B. 
?? v?? ?? ?? 
C. ???? ?? 
D. ???? v?? ??    [[JEE Main 2024 (Online) 31st January Evening Shift]] 
Ans: (a) 
f
K
 = ?? mgcos ?? = 0.1×
50 × v3
2
 = 2.5v3 N
 
Page 2


JEE Mains Previous Year Questions 
(2021-2024): Friction 
2024 
Q1: Consider a block and trolley system as shown in figure. If the coefficient of kinetic friction 
between the trolley and the surface is 0.04 , the acceleration of the system in ????
-?? is : 
(Consider that the string is massless and unstretchable and the pulley is also massless and 
frictionless): 
 
 
A. 1.2 
B. 4 
(C. 3 
D. 2      [JEE Main 2024 (Online) 1st February Morning Shift] 
Ans: (d) 
60 - ?? ?? = (20 + 6)?? 
60 - 200 × 0.04 = 26?? ? ?? = 2 m/s
2
 
Q2: A block of mass ?? ???? is placed on a rough inclined surface as shown in the figure. If ?? ?? ???? 
 is the force 
required to just move the block up the inclined plane and ?? ? ? 
?? is the force required to just prevent the 
block from sliding down, then the value of |?? ?? ???? 
| - |?? ?? ???? 
| is : [Use ?? = ???? ?? /?? ?? ] 
A. ?? v?? ?? 
B. 
?? v?? ?? ?? 
C. ???? ?? 
D. ???? v?? ??    [[JEE Main 2024 (Online) 31st January Evening Shift]] 
Ans: (a) 
f
K
 = ?? mgcos ?? = 0.1×
50 × v3
2
 = 2.5v3 N
 
 
F
1
 = mgsin ?? + f
K
 = 25 + 2.5v3
 
 
 
F
2
= mgsin ?? - f
K
 = 25 - 2.5v3
 ? F
1
- F
2
= 5v3 N
 
 
Q3: In the given arrangement of a doubly inclined plane two blocks of masses ?? and ?? are placed. 
The blocks are connected by a light string passing over an ideal pulley as shown. The coefficient of 
friction between the surface of the plane and the blocks is 0.25 . The value of ?? , for which ?? = ???? ???? 
will move down with an acceleration of ?? ?? /?? ?? , is: (take ?? = ???? ?? /?? ?? and ?????? ????
°
= ?? /?? ) 
Page 3


JEE Mains Previous Year Questions 
(2021-2024): Friction 
2024 
Q1: Consider a block and trolley system as shown in figure. If the coefficient of kinetic friction 
between the trolley and the surface is 0.04 , the acceleration of the system in ????
-?? is : 
(Consider that the string is massless and unstretchable and the pulley is also massless and 
frictionless): 
 
 
A. 1.2 
B. 4 
(C. 3 
D. 2      [JEE Main 2024 (Online) 1st February Morning Shift] 
Ans: (d) 
60 - ?? ?? = (20 + 6)?? 
60 - 200 × 0.04 = 26?? ? ?? = 2 m/s
2
 
Q2: A block of mass ?? ???? is placed on a rough inclined surface as shown in the figure. If ?? ?? ???? 
 is the force 
required to just move the block up the inclined plane and ?? ? ? 
?? is the force required to just prevent the 
block from sliding down, then the value of |?? ?? ???? 
| - |?? ?? ???? 
| is : [Use ?? = ???? ?? /?? ?? ] 
A. ?? v?? ?? 
B. 
?? v?? ?? ?? 
C. ???? ?? 
D. ???? v?? ??    [[JEE Main 2024 (Online) 31st January Evening Shift]] 
Ans: (a) 
f
K
 = ?? mgcos ?? = 0.1×
50 × v3
2
 = 2.5v3 N
 
 
F
1
 = mgsin ?? + f
K
 = 25 + 2.5v3
 
 
 
F
2
= mgsin ?? - f
K
 = 25 - 2.5v3
 ? F
1
- F
2
= 5v3 N
 
 
Q3: In the given arrangement of a doubly inclined plane two blocks of masses ?? and ?? are placed. 
The blocks are connected by a light string passing over an ideal pulley as shown. The coefficient of 
friction between the surface of the plane and the blocks is 0.25 . The value of ?? , for which ?? = ???? ???? 
will move down with an acceleration of ?? ?? /?? ?? , is: (take ?? = ???? ?? /?? ?? and ?????? ????
°
= ?? /?? ) 
 
A. ?? .?? ???? 
B. ?? .?? ???? 
C. ?? ???? 
D. ?? .???? ????   [JEE Main 2024 (Online) 31st January Morning Shift] 
Ans: (a) 
 
For M block 
10 gsin 53
°
- ?? (10 g)cos 53
°
- T = 10 × 2
 T = 80 - 15- 20
 T = 45 N
 
For m block 
T - mgsin 37
°
- ?? mgcos 37
°
= m × 2
45 = 10 m
 m = 4.5 kg
 
Q4: A block of mass ?? is placed on a surface having vertical crossection given by ?? = ?? ?? /?? . If 
coefficient of friction is 0.5 , the maximum height above the ground at which block can be placed 
without slipping is: 
A. ?? /?? ?? 
Page 4


JEE Mains Previous Year Questions 
(2021-2024): Friction 
2024 
Q1: Consider a block and trolley system as shown in figure. If the coefficient of kinetic friction 
between the trolley and the surface is 0.04 , the acceleration of the system in ????
-?? is : 
(Consider that the string is massless and unstretchable and the pulley is also massless and 
frictionless): 
 
 
A. 1.2 
B. 4 
(C. 3 
D. 2      [JEE Main 2024 (Online) 1st February Morning Shift] 
Ans: (d) 
60 - ?? ?? = (20 + 6)?? 
60 - 200 × 0.04 = 26?? ? ?? = 2 m/s
2
 
Q2: A block of mass ?? ???? is placed on a rough inclined surface as shown in the figure. If ?? ?? ???? 
 is the force 
required to just move the block up the inclined plane and ?? ? ? 
?? is the force required to just prevent the 
block from sliding down, then the value of |?? ?? ???? 
| - |?? ?? ???? 
| is : [Use ?? = ???? ?? /?? ?? ] 
A. ?? v?? ?? 
B. 
?? v?? ?? ?? 
C. ???? ?? 
D. ???? v?? ??    [[JEE Main 2024 (Online) 31st January Evening Shift]] 
Ans: (a) 
f
K
 = ?? mgcos ?? = 0.1×
50 × v3
2
 = 2.5v3 N
 
 
F
1
 = mgsin ?? + f
K
 = 25 + 2.5v3
 
 
 
F
2
= mgsin ?? - f
K
 = 25 - 2.5v3
 ? F
1
- F
2
= 5v3 N
 
 
Q3: In the given arrangement of a doubly inclined plane two blocks of masses ?? and ?? are placed. 
The blocks are connected by a light string passing over an ideal pulley as shown. The coefficient of 
friction between the surface of the plane and the blocks is 0.25 . The value of ?? , for which ?? = ???? ???? 
will move down with an acceleration of ?? ?? /?? ?? , is: (take ?? = ???? ?? /?? ?? and ?????? ????
°
= ?? /?? ) 
 
A. ?? .?? ???? 
B. ?? .?? ???? 
C. ?? ???? 
D. ?? .???? ????   [JEE Main 2024 (Online) 31st January Morning Shift] 
Ans: (a) 
 
For M block 
10 gsin 53
°
- ?? (10 g)cos 53
°
- T = 10 × 2
 T = 80 - 15- 20
 T = 45 N
 
For m block 
T - mgsin 37
°
- ?? mgcos 37
°
= m × 2
45 = 10 m
 m = 4.5 kg
 
Q4: A block of mass ?? is placed on a surface having vertical crossection given by ?? = ?? ?? /?? . If 
coefficient of friction is 0.5 , the maximum height above the ground at which block can be placed 
without slipping is: 
A. ?? /?? ?? 
B. ?? /?? ?? 
C. ?? /?? ?? 
D. ?? /?? ??    [JEE Main 2024 (Online) 30th January Evening Shift] 
Ans: (d) 
Explanation 
dy
dx
= tan ?? =
x
2
= ?? =
1
2
x = 1,y = 1/4
 
Q5: Given below are two statements: 
Statement (I) : The limiting force of static friction depends on the area of contact and independent of 
materials. 
Statement (II) : The limiting force of kinetic friction is independent of the area of contact and depends 
on materials. 
In the light of the above statements, choose the most appropriate answer from the options given 
below: 
A. Statement I is incorrect but Statement II is correct 
B. Both Statement I and Statement II are correct 
C. Both Statement I and Statement II are incorrect 
D. Statement I is correct but Statement II is incorrect   [JEE Main 2024 (Online) 27th January Evening 
Shift] 
Ans: (a) 
Let's analyze both statements: 
Statement (I): The limiting force of static friction depends on the area of contact and independent of 
materials. 
This statement is incorrect. The limiting force of static friction does not depend on the area of contact 
but is dependent on the materials in contact. According to the law of static friction, the maximum static 
frictional force ?? ?? that can occur before motion commences is given by the product of the coefficient of 
static friction ?? ?? and the normal reaction force ?? : 
?? ?? = ?? ?? × ?? 
The coefficient ?? ?? is a property that depends on the materials in contact, not on the area of contact. The 
normal force ?? is the force perpendicular to the surfaces in contact, influenced by the weight of the 
object and any other perpendicular forces acting upon it. 
Statement (II): The limiting force of kinetic friction is independent of the area of contact and depends on 
materials. 
This statement is correct. Once an object is in motion, the kinetic frictional force ?? ?? opposing its motion 
is given by the product of the coefficient of kinetic friction ?? ?? and the normal force ?? : 
?? ?? = ?? ?? × ?? 
The coefficient ?? ?? , like ?? ?? , is also a property dependent on the materials of the surfaces in contact. It 
generally has a lower value than ?? ????
 which is why objects tend to be easier to keep moving once they've 
started. The kinetic frictional force is independent of the area of contact between the two surfaces. 
Given these explanations, the correct answer would be: 
Option A: Statement I is incorrect but Statement II is correct. 
Page 5


JEE Mains Previous Year Questions 
(2021-2024): Friction 
2024 
Q1: Consider a block and trolley system as shown in figure. If the coefficient of kinetic friction 
between the trolley and the surface is 0.04 , the acceleration of the system in ????
-?? is : 
(Consider that the string is massless and unstretchable and the pulley is also massless and 
frictionless): 
 
 
A. 1.2 
B. 4 
(C. 3 
D. 2      [JEE Main 2024 (Online) 1st February Morning Shift] 
Ans: (d) 
60 - ?? ?? = (20 + 6)?? 
60 - 200 × 0.04 = 26?? ? ?? = 2 m/s
2
 
Q2: A block of mass ?? ???? is placed on a rough inclined surface as shown in the figure. If ?? ?? ???? 
 is the force 
required to just move the block up the inclined plane and ?? ? ? 
?? is the force required to just prevent the 
block from sliding down, then the value of |?? ?? ???? 
| - |?? ?? ???? 
| is : [Use ?? = ???? ?? /?? ?? ] 
A. ?? v?? ?? 
B. 
?? v?? ?? ?? 
C. ???? ?? 
D. ???? v?? ??    [[JEE Main 2024 (Online) 31st January Evening Shift]] 
Ans: (a) 
f
K
 = ?? mgcos ?? = 0.1×
50 × v3
2
 = 2.5v3 N
 
 
F
1
 = mgsin ?? + f
K
 = 25 + 2.5v3
 
 
 
F
2
= mgsin ?? - f
K
 = 25 - 2.5v3
 ? F
1
- F
2
= 5v3 N
 
 
Q3: In the given arrangement of a doubly inclined plane two blocks of masses ?? and ?? are placed. 
The blocks are connected by a light string passing over an ideal pulley as shown. The coefficient of 
friction between the surface of the plane and the blocks is 0.25 . The value of ?? , for which ?? = ???? ???? 
will move down with an acceleration of ?? ?? /?? ?? , is: (take ?? = ???? ?? /?? ?? and ?????? ????
°
= ?? /?? ) 
 
A. ?? .?? ???? 
B. ?? .?? ???? 
C. ?? ???? 
D. ?? .???? ????   [JEE Main 2024 (Online) 31st January Morning Shift] 
Ans: (a) 
 
For M block 
10 gsin 53
°
- ?? (10 g)cos 53
°
- T = 10 × 2
 T = 80 - 15- 20
 T = 45 N
 
For m block 
T - mgsin 37
°
- ?? mgcos 37
°
= m × 2
45 = 10 m
 m = 4.5 kg
 
Q4: A block of mass ?? is placed on a surface having vertical crossection given by ?? = ?? ?? /?? . If 
coefficient of friction is 0.5 , the maximum height above the ground at which block can be placed 
without slipping is: 
A. ?? /?? ?? 
B. ?? /?? ?? 
C. ?? /?? ?? 
D. ?? /?? ??    [JEE Main 2024 (Online) 30th January Evening Shift] 
Ans: (d) 
Explanation 
dy
dx
= tan ?? =
x
2
= ?? =
1
2
x = 1,y = 1/4
 
Q5: Given below are two statements: 
Statement (I) : The limiting force of static friction depends on the area of contact and independent of 
materials. 
Statement (II) : The limiting force of kinetic friction is independent of the area of contact and depends 
on materials. 
In the light of the above statements, choose the most appropriate answer from the options given 
below: 
A. Statement I is incorrect but Statement II is correct 
B. Both Statement I and Statement II are correct 
C. Both Statement I and Statement II are incorrect 
D. Statement I is correct but Statement II is incorrect   [JEE Main 2024 (Online) 27th January Evening 
Shift] 
Ans: (a) 
Let's analyze both statements: 
Statement (I): The limiting force of static friction depends on the area of contact and independent of 
materials. 
This statement is incorrect. The limiting force of static friction does not depend on the area of contact 
but is dependent on the materials in contact. According to the law of static friction, the maximum static 
frictional force ?? ?? that can occur before motion commences is given by the product of the coefficient of 
static friction ?? ?? and the normal reaction force ?? : 
?? ?? = ?? ?? × ?? 
The coefficient ?? ?? is a property that depends on the materials in contact, not on the area of contact. The 
normal force ?? is the force perpendicular to the surfaces in contact, influenced by the weight of the 
object and any other perpendicular forces acting upon it. 
Statement (II): The limiting force of kinetic friction is independent of the area of contact and depends on 
materials. 
This statement is correct. Once an object is in motion, the kinetic frictional force ?? ?? opposing its motion 
is given by the product of the coefficient of kinetic friction ?? ?? and the normal force ?? : 
?? ?? = ?? ?? × ?? 
The coefficient ?? ?? , like ?? ?? , is also a property dependent on the materials of the surfaces in contact. It 
generally has a lower value than ?? ????
 which is why objects tend to be easier to keep moving once they've 
started. The kinetic frictional force is independent of the area of contact between the two surfaces. 
Given these explanations, the correct answer would be: 
Option A: Statement I is incorrect but Statement II is correct. 
2023 
Q1: As shown in the figure a block of mass 10 kg lying on a horizontal surface is pulled by a force F 
acting at an angle 30
°
, with horizontal. For µ
s
 = 0.25 , the block will just start to move for the value of F 
: [Given g = 10 ms
-2
] 
 
 
(a) 25.2 N 
(b) 35.7 N 
(c) 20 N 
(d) 33.3 N 
Ans: (a)