Explore topic-wise InterviewSolutions in Current Affairs.

A $150\text{m}$ long train accelerates uniformly from rest. If the front of the train passes a railway worker $50\text{m}$ away from the station at a speed of $25\text{m/s}$, what will be the speed of the back part of the train as it passes the worker?

A boy standing on a stationary lift (open from above) throws a ball upwards with the maximum initial speed he can, equal to 49 m/s. How much time does the ball take to return to his hands? If the lift starts moving up with a uniform speed of 5 m/s and the boy again throws the ball up with the maximum speed he can, how long does the ball take to return to his hands?

Water rises to a height $h$ in a capillary tube of area of cross-section $a$. To what height will water rise in a capillary tube of radius of cross-section 4a?

A rod of length L and cross-section area A lies along the x-axis between x = 0 and x = L. The material obeys Ohm's law and its resistivity varies along the rod according to $\rho \left(x\right)={\rho }_0{e}^{-x/L}$. The total resistance of the rod is

If n is the frequency of rotation of a body, its angular velocity is:

If $y=e^x.\cot x$ then $dy/dx$ will be

A proton is moving in a field of induction $[2\overrightarrow{i}+4\overrightarrow{j}]T$ with velocity $[3\times {10}^7\overrightarrow{i}]m{s}^{-1}$. The force experienced by it will be?

A ladder $20$ ft long leans against a vertical wall. The top end slides downwards at the rate of $2$ ft per second. The rate at which the lower end moves on a horizontal floor when it is $12$ ft from the wall is

The phase of a particle executing simple harmonic motion is $\frac{\pi }{2}$ when it has

[MP PET 1985]

An inclined plane rises 1 in 10. If length of the inclined plane is 5 $m$, find the height of the raised end above the horizontal.

An example of kinetic energy would be:

What is the relationship between the average velocity (v), root mean square velocity (u) and most probable velocity (α)

The equation of a wave travelling on a string is $y=4sin\frac{\pi }{2}⟮8t-\frac{x}{8}⟯$ . If x and y are in cm, then velocity of wave is

[MP PET 1990]

If the energy of a photon corresponding to a wavelength of $6000\stackrel{\circ }{A}is3.32\times {10}^{-19}J$, the photon energy for a wavelength of $4000\stackrel{\circ }{A}$ will be

A road is 10 m wide. Its radius of curvature is 50 m. The outer edge is above the lower edge by a distance of 1.5 m. This road is most suited for the velocity

A small heavy block is attached to the lower end of a light rod of length l which can be rotated about its clamped upper end. What minimum horizontal velocity should the block be given so that it moves in a compete vertical circle?

A body of mass 2 kg is thrown up vertically with K.E. of 490 joule. If the acceleration due to gravity is 9.8 $m/s^2$, then the height at which the K.E. of the body becomes half its original value is given by

A semi circular ring of radius R as shown in figure has charge per unit length $\lambda ={\lambda }_{0}cos\theta$. Electric dipole moment of this ring is.

Find the dimensional formula of ${\epsilon }_0$

A man of mass M stands on a weighing machine in an elevator accelerating upwards with an acceleration $a_0$ . Calculate the reading of the weighing machine

In the shown figure, the block moves downwards with velocity $V_1$, the wedge moves rightwards with velocity $V_2$. Assuming the surface to be smooth and pulley and string to be ideal, the correct relation between $V_1$ and $V_2$ is

A particle moves in a circle of diameter 1.0 cm under the action of a magnetic field of 0.40 T. An electric field of $200V{m}^{-1}$ makes the path straight. Find the charge/mass ratio of the particle.

How many time constants will elapse before the charge on a capacitor falls to 0.1$\%$ of its maximum value in a discharging RC circuit ?

In a horizontal pipeline of uniform cross-section the pressure falls by $8{\text{N/m}}^2$ between two points separated by $1\text{km}$. If oil of density $800{\text{kg/m}}^3$ flows through the pipe, find the change in $K.E$ per $\text{kg}$ of oil at these points.

A square plate of $1\text{m}$ side moves parallel to a second plate with velocity $4\text{m/s}$. A thin layer of water exist between plates. If the viscous force is $2\text{N}$ and the coefficient of viscosity is $0.01\text{Poise}$, then find the distance between the plates.

A particle is projected with a velocity v such that its range on the horizontal plane is twice the greatest height
attained by it. The range of the projectile is (where is acceleration due to gravity)

A heavy uniform chain lies on a horizontal table top. If the coefficient of friction between the chain and the table surface is $0.25$, then the maximum fraction of length of chain that can overhang on the edge of the table is

The space around a magnet where its influence can be detected, is called ___

The potential energy between two atoms in a molecule is given by $U\left(x\right)=\frac{a}{x^{12}}-\frac{b}{x^6}$ where $a$ and $b$ are positive constants and $x$ is the distance between the atoms. The atom is in stable equilibrium when

Figure (15-E7) shows two wave pulses at t = 0 travelling on a string in opposite directions with the same wave

speed $50cm{s}^{-1}.$ Sketch the shape of the string at t = 4 ms, 6 ms, 8 ms, and 12 ms.

A particle executing SHM has velocities $u$ and $v$ and accelerations $a$ and $b$ at two of its positions. Find the shortest distance between these two positions.

A particle is moving in a straight line with SHM. Its velocity has the values $3m/s$ and $2m/s$ when its distances from mean position are $1m$ and $2m$ respectively. Find the length of its path and period of its motion.

A monochromatic light source of intensity 5 mW emits $8\times {10}^{15}$ photons per second. This light ejects photoelectrons from a metal surface. The stopping potential for this setup is 2.0 V. Calculate the work function of the metal.

If $a=(3t^2+2t+1)m/s^2$ is the expression according to which the acceleration of a particle moving along a straight line varies, then the expression for instantaneous velocity at any time $t$ will be (if the particle was initially at rest)

For the masses and ideal-massless pulleys shown in figure find the ratio of magnitudes of accelerations of masses $A$ and $B$. Pulley $C$ is fixed to the ceiling and pulley $D$ is free to move vertically. All strings are inextensible and assume the string length to be equal between the pulley D and C and between the pulley D and the rigid support.

The initial speed of a body of mass $2.0\text{kg}$ is $5.0{\text{ms}}^{-1}$. A force acts for 4 seconds in the direction of motion of the body. The force-time graph is shown in figure. Calculate the impulse of the force and also the final speed of the body.

The potential energy of a particle of mass ‘m’ is given by U = $\frac{1}{2}k{x}^2$ for x < 0 and U = 0 for $x\ge 0$. If total
mechanical energy of the particle is E. Then its speed for positive value of ‘x’ is

Speed can be represented as time /length

A long, hollow conducting cylinder is kept coaxially inside another long, hollow conducting cylinder of larger radius. Both the cylinders are initially electrically neutral.

An electron, a proton and an alpha particle having the same kinetic energy are moving in circular orbits of radii $r_e,r_p,r_{\alpha }$ respectively in uniform magnetic field $B$. The relation between $r_e,r_p,r_{\alpha }$ is

Write symbolically the nuclear${\beta }^{+}$ decay process of $6^{11}\text{C}$ . Is the decayed product X an isotope or isobar of $\left(6^{11}\text{C}\right)$? Given the mass values m $\left(6^{11}\text{C}\right)$ = 11.011434 u and m (X) = 11.009305 u. Estimate the Q-value in this process.

A total charge $Q$ is broken in two parts $Q_1$ and $Q_2$ , and they are placed at a distance $R$ from each other. The maximum force of repulsion between them will occur when

A particle leaves the origin with an initial velocity $\overrightarrow{v}$ = ( $3.00\hat{i}$ ) m/s and a constant acceleration $\overrightarrow{a}$ = ( $-1.00\hat{i}-0.500\hat{j}$ ) m/$s^2$. When it reaches its maximum x coordinate, match its position vector and velocity vector(Coloumn A) with vectors (Coloumn B)?

A closed organ pipe and an open organ pipe of same length produce 2 beats when they are set into vibrations simultaneously in their fundamental mode. The length of open organ pipe is now halved and of closed organ pipe is doubled, the number of beats produced will be

A thermally insulated chamber of volume $2V_0$ is divided by light and frictionless piston of area S into two equal parts A and B. Part A has an ideal gas at pressure $P_0$ and temperature $T_0$ and in part B is the vacuum. A massless spring of force constant K is connected with the piston and the wall of the container as shown. Initially, the spring is unstretched. The gas in chamber A is allowed to expand. Let in equilibrium the spring be compressed by $z_0$ Then.