Explore topic-wise InterviewSolutions in Current Affairs.

A bullet emerges from a gun barrel of length $1.2m$ with a speed of $640m/s$. Assuming constant acceleration, the approximate time that it spends in the barrel after the gun is fired is

A metal ball of mass $10\text{kg}$ is suspended from a massless string of length $2\text{m}$ as shown in figure. Another identical ball of mass $10\text{kg}$ is projected towards the suspended ball. Assuming the collision between the balls to be perfectly elastic, find the minimum value of velocity of second ball so that the first ball just completes the vertical circular motion. [Take $g=10{\text{m/s}}^2$]

Two spherical bubbles coalesce isothermally. $V$ is the consequent change in volume and $S$ is the total change in surface area, then



Let $P$ be atmospheric pressure outside the bubbles and $T$ be surface tension.

1. 1

The average power dissipation in pure capacitive circuit is:

A current carrying loop whose magnetic moment is at ${30}^{\circ }$ with a uniform external magnetic field of $0.16\text{T}$ experiences a torque of magnitude $0.032\text{Nm}$. If the coil is free to rotate, its potential energies when it is in stable and unstable equilibrium are respectively

In a conductivity cell the two platinum electrodes, each of area $10{\text{cm}}^2,$ are fixed $1.5\text{cm}$ apart. The cell contains $0.05\text{N}$ solution of a salt. If the two electrodes are just half dipped into the solution which has a resistance of $50\Omega$, find specific conductance of the salt solution.

A stationary body explodes into four identical fragments such that three of them fly off mutually perpendicular to each other, each with same KE, $E_0$. The energy of explosion will be:

Find the minimum value of a function $y$, represented as $y=x^3-3x^2+6$.

From the top of a $19.6\text{m}$ high tower, a ball is thrown horizontally. If the line joining the point of projection to the point where it hits the ground, makes an angle of ${45}^{\circ }$ with the horizontal, then the initial velocity of the ball is

1. 0.871

Using Bohr's Atomic Model, match the following columns.



$($Symbols $n$ and $Z$ have their usual meanings$)$

To see $2$ times magnified image in concave mirror, object should be placed at $xcm$ from mirror. Find $x$. $(f=40cm)$

A particle describes a horizontal circle of radius $r$ on the smooth surface of an inverted cone as shown in the figure. The height of plane of circle above vertex is $h$. The speed of the particle should be

The graph shows the number of hotdogs sold in a particualr time. Choose the correct option for the equation represented in the graph given below.

The rotation of the earth having radius $R$ about its axis speeds up to a value such that a man at latitude of ${60}^{\circ }$ feels weightlessness. The duration of the day in such a case is

In a meter bridge, a standard resistor of $R\Omega$ is connected in the left gap and the two wires A and B are connected one after the other in the right gap. The balancing length measured from the left is $50cm$ for either of them. If the two wires are connected in series and put in the right gap, balancing length measured from left would be (in $cm$)

Unpolarized light falls on two polarizing sheets placed one on top of the other. What must be the angle between the characteristic directions of the sheets, if the intensity of the final transmitted light is one-third the maximum intensity of the first transmitted beam?

In Quincke's experiment, the sound intensity has a minimum value I at a particular position. As the sliding tube is pulled out by a distance of 16.5 mm, the intensity increases to a maximum of 9 I. Take the speed of sound in air to be 330 m/s. (a) Find the frequency of the sound source. (b) Find the ratio of the amplitudes of the two waves arriving at the detector assuming that it does not change much between the positions of minimum intensity and maximum intensity.

Two particles $A$ and $B$ are moving with uniform velocities as shown in the figure given below at $t=0$
Find out shortest distance between two particles.

A particle of mass $50\text{kg}$ thrown into the tunnel from point $\text{A}$ inside the earth, the tunnel is $d$ away from the center of the earth. A particle oscillates about a point $\text{C}$ inside the tunnel due to the gravitational force towards the centre. Calculate the time period of oscillation. (Radius of earth $=6.378\times {10}^6\text{m})$

If two rods of length L and 3L having coefficient of expansion $\alpha$ and $4\alpha$ respectively are connected, average coefficient of linear expansion equals to:

The bob of a simple pendulum has mass $2g$ and a charge of $5.0\mu C$. It is at rest in a uniform horizontal electric field of intensity $2000V/m$. At equilibrium, the angle that the pendulum makes with the vertical is (take $g=10m/s^2)$.

A small meteorite of mass 'm' travelling towards the centre of earth strikes the earth at the equator. The earth is a uniform sphere of mass 'M' and radius 'R'. The length of the day was 'T' before the meteorite struck. After the meteorite strikes the earth, the length of day increases (in sec) by

A $4\text{kg}$ block is placed on top of a long $12\text{kg}$ block, which is accelerating along a smooth horizontal table at $a=5.2\text{m}/{\text{s}}^2$ under application of an external constant force. let minimum co-efficient of friction between the two blocks which will prevent the $4\text{kg}$ block from sliding is $\mu$ and co-efficient of friction between the blocks is only half of this minimum value i.e., $\frac{\mu }{2}$. Find the amount of heat generated due to sliding between the two blocks during the time in which $12\text{kg}$ block moves $10\text{m}$ starting from rest.

A steel wire of cross sectional area $0.05{\text{cm}}^2$ is under a tension of $15\text{N}$. Find the decrease in the cross-sectional area. Young's modulus of steel = $2\times {10}^{11}{\text{N/m}}^2$ and Poisson's ratio = $0.3$.

In Bohr series of lines of hydrogen spectrum, the emission of a line from the red end corresponds to which one of the following inner-orbit jump of the electron in a hydrogen atom?

For the given arrangement, a fixed finite line charge is kept in front of a block at equilibrium having $-10\text{nC}$ charge on it. Block and finite line charge are along same line. If in equilibrium, extension of spring is $10\text{cm}$ then spring constant $\left(K\right)$ is

Two blocks of masses $m_1=4kg$ and $m_2=6kg$ are connected by a string of negligible mass passing over a frictionless pulley as shown in the figure. The coefficient of friction between block $m_1$ and the horizontal surface is 0.4. When the system is released, the masses $m_{1}and{m}_2$ start accelerating. What additional mass $m$ should be placed over mass $m_1$ so that the masses $(m_1+m)$ slide with a uniform speed?

Two strings X and Y of a sitar produces a beat of frequency 4Hz. When the tension of string Y is slightly increased, the beat frequency is found to be 2 Hz. If the frequency of X is 300 Hz, then the original frequency of Y was: