Explore topic-wise InterviewSolutions in Current Affairs.

Find the dimension of 'The coefficient of the linear expansion' .

Hi today I am learning the chapter electrostatics

in the chapter there is one question that is in the printer the toner particles are get attracted to the paper by the static electricity I have one doubt in that how the toner particles get attracted towards the paper and what is the actual process accurate that and why the paper which was taken after the xerox was hot in condition please tell me with a pic thank you

A particle free to move along the x-axis has potential energy given by $U\left(x\right)=k(1-e^{-x^2})$ For $-\infty <x<\infty$, where k is a positive constant of appropriate dimensions. Then

A Charge is fired through a magnetic field. The magnetic force acting on it is maximum when the angle between the direction of motion and magnetic field is

The force between two charges at a distance ‘r’ is ‘F’. What will happen to the force if a metal rod is inserted between the charges?

Two particles, one with constant velocity $50{\text{ms}}^{-1}$ and the other with uniform acceleration $10{\text{ms}}^{-2}$, start moving simultaneously from the same place in the same direction. When will the accelerated particle be $125\text{m}$ ahead of the other particle?

If mean wavelength of light radiated by 100 W lamp is 5000 $\stackrel{\circ }{A}$, then number of photons radiated per second are

An extensible string is woung over a rough pulley of mass $m_1$ and radius R; and a cylinder of mass $m_2$ and radius R such that as the cylinder rolls down the string un-wounds over the pulley as well the cylinder. Find the linear acceleration of the cylinder.

The displacement x of a particle along a straight line at time t is given by $x=a_0+a_{1}t+a_2{t}^2$.The acceleration of the particle is

A body, whose momentum is constant, must have constant

A coin is dropped in a lift. It takes time $t_1$ to reach the floor when lift is stationary. It takes time $t_2$ when lift is moving up with constant acceleration. Then

Match the block diagrams of block of mass, m, with their corresponding free body diagram.

(Bodies are at rest with respect to ground)

An engine generates a power of 10 kW. In how much time will it raise a mass of 200 kg through a height of 40m.

If a simple pendulum oscillates with an amplitude of 50 mm and time period of 2 sec, then its maximum velocity is

[AIIMS 1998; MH CET 2000; DPMT 2000]

One end of a light spring of spring constant k is fixed to a wall and the other end is tied to a block placed on a smooth horizontal surface. In a displacement, the work done by the spring is $\frac{1}{2}k{x}^2$. The possible cases are

The distance covered by a particle thrown in a vertical plane in horizontal and vertical directions at any instance of time $t$ are $x=\sqrt{21}tm$ and $y=(2t-4t^2)m$ respectively. The initial velocity of the particle (in $m/s$) is

The strength of the magnetic field at a point r near a long straight current carrying wire is B. The field at a distance $\frac{r}{2}$ will be

[MP PMT 1990]

A sphere of mass $M$ and radius $R_2$ has a concentric cavity of radius $R_1$ as shown in figure. The force $F$ exerted by the sphere on a particle of mass $m$ located at a distance $r$ from the centre of sphere varies as $(0\le r\le \infty )$

What is the value of 0!

A radio transmitter operates at a frequency of 880 kHz and a power of 10 kW. The number of photons emitted per second are

The figure shows pressure versus density graph for an ideal gas at two temperature $T_1$ and $T_2$:

If $\overrightarrow{P}.\overrightarrow{Q}=PQ,$ then the angle between $\overrightarrow{P}$ and $\overrightarrow{Q}$ is

A particle of mass m and charge q starts moving from the origin under the action of an electric field $\overrightarrow{E}=E_0\hat{i}$ and magnetic field $\overrightarrow{B}=B_0\hat{k}$. Its velocity at $(x_0,0,0)$ is $(4\hat{i}+3\hat{j})$. Then

Two superimposing waves are represented by the equations $x_1=5\sin 2\pi (20t-0.1x)$ and $x_2=10\sin 2\pi (20t-0.2x)$ where $x$ and amplitude of each wave are given in meters and $t$ is in seconds. Find the ratio of maximum intensity to minimum intensity.

The fundamental frequency in an open organ pipe is equal to the third harmonic of a closed organ pipe. If the length of the closed organ pipe is $20cm$, the length of the open organ pipe is

Given vector $\overrightarrow{A}=2\hat{i}+3\hat{j},$ the angle between $\overrightarrow{A}$ and y-axis is

Find the equivalent resistance between A and E (Resistance of each resistor is R).

The magnetic field at a point $P$ which is at the distance of $4$ $cm$ from a long current carrying wire is ${10}^{-3}T$, the magnetic field at a distance $12$ $cm$ from the current carrying wire will be

A and B are two identical rods of internal resistance $r=1\Omega .$ If $R=2\Omega ,V_A=4m/s,V_B=3m/s$, length of rods is 1 m, then current in R is (Magnetic field is 2T)

A mass-spring system oscillates such that the mass moves on a rough surface having coefficient of friction $\mu$. It is compressed by a distance a from its normal length and, on being released, it moves to a distance $b$ from its equilibrium position. The decrease in amplitude for one half-cycle $(-atob)$ is

A small block of mass $200\text{g}$ is pressed against a horizontal spring fixed at one end to compress the spring through $5\text{cm}$. The spring constant is $100\text{N/m}$. The spring is located on a frictionless horizontal plank located at a height of $3\text{m}$ from the ground. When the block is released, what horizontal distance will it travel (after leaving the plank) before it hits the ground. (Take $g=10{\text{m/s}}^2$).

Find the acceleration of block $A$ and $B$? Take $g=10m/s^2$

A particle, which is constrained to move along the $x-$ axis, is subjected to a force from the origin as $F\left(x\right)=-kx+a{x}^3$. Here $k$ and $a$ are positive constants. For $x=0$, the functional form of the potential energy $U\left(x\right)$ of particle is

A block of mass 2$M$ is attached to a massless spring with spring constant $k$. This block is connected to two other blocks of masses $M$ and $2M$ using two massless pulleys and strings. The accelerations of the blocks are $a_1,a_2$ and $a_3$ as shown in the figure. The system is released from rest with the spring in its unstretched state. The maximum extension of the spring is $x_0$. Which of the following option(s) is/are correct?

[$g$ is the acceleration due to gravity. Neglect friction]

An object of m kg with speed of v m/s strikes a wall at an angle q and rebounds at the same speed and same angle. The magnitude of the change in momentum of the object will be

A planet has radius equal to $2R_E$ and density is equal to $4{\rho }_E$. If the value of escape speed at surface of planet is $\alpha$ times $v_E$ ($v_E$ is escape speed on earth, $R_E$ is radius of earth and ${\rho }_E$ is the density of earth) then,

A block $B$ is pushed momentarily along the horizontal surface with an initial velocity $v$. If $\mu$ is the coefficient of sliding friction between $B$ and the surface, block $B$ will come to rest after a time

Given in the figure are two blocks A and B of weight $20N$ and $100N$, respectively. These are being pressed against a wall by a force $F$ as shown. If the coefficient of friction between the blocks is $0.1$ and between block B and the wall is $0.15$, the frictional force applied by the wall on block B is

A ball moving with speed u hits another identical ball at rest. The two balls stick together after collision and the loss of energy is all converted only to heat. If specific heat of the material of the balls is S, the temperature rise resulting from the collision is

Select the correct figure that represents the stable equilibrium point.

A parallel plate capacitor has two layers of dielectric as shown in figure. This capacitor is connected across a battery, then the ratio of potential difference across the dielectric layers is:

Let $\overrightarrow{a}=\hat{i}+\hat{j}+\hat{k}$, $\overrightarrow{b}=\hat{i}-\hat{j}+\hat{k}$ and $\overrightarrow{c}=\hat{i}-\hat{j}-\hat{k}$ be three vectors. A vector $\overrightarrow{v}$ in the plane of $\overrightarrow{a}$ and $\overrightarrow{b}$, whose projection on $\overrightarrow{c}$ is $\frac{1}{\sqrt{3}}$, is given by