JEE Main Physics — Mechanics previous year questions with solutions.
The bob of a pendulum was released from a horizontal position. The length of the pendulum is $10m$. If it dissipates $10%$ of its initial energy against air resistance, the speed with which the bob arrives at the lowest point is: [Use, $g=10m{s}^{-2}$ ]
A given object takes $\mathrm{n}$ times the time to slide down $45^{\circ}$ rough inclined plane as it takes the time to slide down an identical perfectly smooth $45^{\circ}$ inclined plane. The coefficient of kinetic friction between the object and the surface of inclined plane is :
A clock has $75 \mathrm{~cm}, 60 \mathrm{~cm}$ long second hand and minute hand respectively. In 30 minutes duration the tip of second hand will travel $x$ distance more than the tip of minute hand. The value of $x$ in meter is nearly (Take $\pi=3.14$ ) :
A $2 \mathrm{~kg}$ brick begins to slide over a surface which is inclined at an angle of $45^{\circ}$ with respect to horizontal axis. The co-efficient of static friction between their surfaces is:
Applying the principle of homogeneity of dimensions, determine which one is correct, where $T$ is time period, $G$ is gravitational constant, $M$ is mass, $r$ is radius of orbit.
What is the range of the ball along the inclined plane?
A heavy box of mass $50 \mathrm{~kg}$ is moving on a horizontal surface. If co-efficient of kinetic friction between the box and horizontal surface is 0.3 then force of kinetic friction is :
A wooden block, initially at rest on the ground, is pushed by a force which increases linearly with time $t$. Which of the following curve best describes acceleration of the block with time:
Four identical particles of mass $m$ are kept at the four corners of a square. If the gravitational force exerted on one of the masses by the other masses is $(\frac{2\sqrt{2}+1}{32})\frac{G{m}^{2}}{{L}^{2}}$, the length of the sides of the square is
The resultant of two vectors $\vec{A}$ and $\vec{B}$ is perpendicular to $\vec{A}$ and its magnitude is half that of $\vec{B}$. The angle between vectors $\vec{A}$ and $\vec{B}$ is ______ $\circ$.
A block of mass $5\mathrm{kg}$ is placed on a rough inclined surface as shown in the figure. If ${\vec{F}}_{1}$ is the force required to just move the block up the inclined plane and ${\vec{F}}_{2}$ is the force required to just prevent the block from sliding down, then the value of $|{\vec{F}}_{1}|-|{\vec{F}}_{2}|$ is: [Use $g=10m{s}^{-2}$] 
Match List I with List II $\begin{array}{|l|l|r|l|} \hline \text{ LIST I } & \text{ LIST II } \\ \hline \text{A.} & \text{Torque} & \text{I.} & {\left[M^1 L^1 T^{-2} A^{-2}\right]} \\ \hline \text{B.} & \text{Magnetic field} & \text{II.} & {\left[L^2 A^1\right]} \\ \hline \text{C.} & \text{Magnetic moment} & \text{III.} & {\left[M^1 T^{-2} A^{-1}\right]} \\ \hline \text{D.} & \text{Permeability of free space} & \text{IV.} & {\left[M^1 L^2 T^{-2}\right]} \\ \hline \end{array}$ Choose the correct answer from the options given below:
An elastic spring under tension of $3 \mathrm{~N}$ has a length $a$. Its length is $b$ under tension $2 \mathrm{~N}$. For its length $(3 a-2 b)$, the value of tension will be______$\mathrm{N}$.
Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R) Assertion (A) : The property of body, by virtue of which it tends to regain its original shape when the external force is removed, is Elasticity. Reason (R) : The restoring force depends upon the bonded inter atomic and inter molecular force of solid. In the light of the above statements, choose the correct answer from the options given below :
The depth below the surface of sea to which a rubber ball be taken so as to decrease its volume by $0.02%$ is _____ $m$. (Take density of sea water $={10}^{3}\mathrm{kg}{m}^{-3}$, Bulk modulus of rubber $=9\times {10}^{8}N{m}^{-2}$, and $g=10m{s}^{-2}$)
Two metallic wires $P$ and $Q$ have same volume and are made up of same material. If their area of cross sections are in the ratio $4:1$ and force ${F}_{1}$ is applied to $P$, an extension of $\Delta l$ is produced. The force which is required to produce same extension in $Q$ is ${F}_{2}$. The value of $\frac{{F}_{1}}{{F}_{2}}$ is ______.
A bullet of mass $50 \mathrm{~g}$ is fired with a speed $100 \mathrm{~m} / \mathrm{s}$ on a plywood and emerges with $40 \mathrm{~m} / \mathrm{s}$. The percentage loss of kinetic energy is :
The excess pressure inside a soap bubble is thrice the excess pressure inside a second soap bubble. The ratio between the volume of the first and the second bubble is:
A particle moving in a circle of radius $R$ with uniform speed takes time $T$ to complete one revolution. If this particle is projected with the same speed at an angle $\theta$ to the horizontal, the maximum height attained by it is equal to $4R$. The angle of projection $\theta$ is then given by :
A body starts falling freely from height $H$ hits an inclined plane in its path at height $h$. As a result of this perfectly elastic impact, the direction of the velocity of the body becomes horizontal. The value of $\frac{H}{h}$ for which the body will take the maximum time to reach the ground is _____.
The dimensional formula of angular impulse is :
Identify the physical quantity that cannot be measured using spherometer :
The acceleration due to gravity on the surface of earth is $g$. If the diameter of earth reduces to half of its original value and mass remains constant, then acceleration due to gravity on the surface of earth would be :
A light string passing over a smooth light fixed pulley connects two blocks of masses ${m}_{1}$ and ${m}_{2}$. If the acceleration of the system is $\frac{g}{8}$, then the ratio of masses is 