Explore topic-wise InterviewSolutions in Current Affairs.

A ball is hit by a batsman at an angle of ${37}^{\circ }$ as shown in the figure. With what minimum velocity should the man standing at $P$ run so that he catches the ball before it strikes the ground. Assume that height of a man is negligible in comparison to the maximum height of projectile. $(g=10m/s^2)$

Why energy is inversely proportional to wavelength? Explain it

Column-I: Subshell Column-II: Number of spherical nodes Column-III: Radial plot

The only correct combination for the last electron of $C{l}^{-}$ is:

When two soap bubbles of radius $r_1$ and $r_2$ ($r_2$ > $r_1$) coalesce, the radius of curvature of common surface is

Difference between work function and threshold frequency

Two point P and Q diametrically opposite on a disc of radius $R$ have velocities $v$ and $2v$ as shown in figure. Find the angular speed of Q w.r.t P.

Two identical glass bulbs are interconnected by a thin glass tube. A gas is filled in these bulbs at N.T.P. If one bulb is placed in ice and another bulb is placed in hot bath, then the pressure of the gas becomes 1.5 times. The temperature of hot bath will be

A block of mass $m$ is placed on an inclined plane of angle $\theta$. The coefficient of friction between the block and the plane is $\mu$ and $\tan \theta >\mu$. The block is held stationary by applying a force $P$ parallel to the inclined plane. The direction of force pointing up the plane is taken to be positive. As force $P$ is varied from $P_1=mg(\sin \theta -\mu \cos \theta )$ to $P_2=mg(\sin \theta +\mu \cos \theta )$, then the graph of frictional force $f$ versus $P$ graph will look like:

A car is moving along a straight line. It's displacement (x) - time (t) graph is shown. Match the entries in column I with points on graph as in Column-II.

Column I

(p) x $\to$ negative,v $\to$ positive,a $\to$ positive (q) x $\to$ positive, v $\to$ negative,a $\to$ negative

(r) x $\to$ negative,v $\to$ negative,a $\to$ positive (s) x $\to$ positive, v $\to$ positive,a $\to$ negative.

Column II

Two blocks of masses 10 kg and 30 kg are placed along a vertical line. The first block is raised through a height of 7 cm. By what distance should the second mass be moved to raise the centre of mass by 1 cm?

If at same pressure, the densities of two gases are ${\rho }_1$ and ${\rho }_2$ respectively,then the ratio of r.m.s. velocity of their molecules respectively are

A ball is thrown at an angle ${53}^{\circ }$ with a velocity of 50 $m{s}^{-1}$. Calculate the difference between the velocities at the two instants when the body is 20 m above the ground

Galileo writes that for angles of projection of a projectile at angles $(45+\theta )and(45-\theta )$, the horizontal ranges described by the projectile are in the ratio of $(if\theta \le 45)$

At $t=0$, a transverse wave pulse travelling along positive $x-$direction with speed $3m/s$ in a string described by the function $y=\frac{9}{x^2}$ given that $x\ne 0$. Transverse velocity of particle at $x=3m$ and $t=3s$ will be

Find the total impulse acting on a body up to 8 seconds from the $F-t$ graph shown.

A capacitor of capacitance $100\mu F$ is connected to a battery of 20 volts for a long time and then disconnected from it. It is now connected across a long solenoid having 4000 turns per metre. It is found that the potential difference across the capacitor drops to $90\%$ of its maximum value in 2.0 seconds. Estimate the average magnetic field produced at the centre of the solenoid during this period.

A particle of mass M is moving in a horizontal circle of radius R with uniform speed V. When it moves from one point to a diametrically opposite point, its

The ratio of concentration of electrons and that of the holes in a semiconductor is $\frac{7}{5}$ and ratio of currents is $\frac{7}{4}$, then what is the ratio of their drift velocities?

The pressure variation equation of a sound wave propagating in a medium with pressure amplitude $P_0$ is

$P=P_{0}sin\omega (t-\frac{x}{v})$

Inference:

In the tube where this wave is propagating if we measure pressure, then the maximum pressure measured will be _{$P_0$} atm and Minimum pressure measured will be _{$-P_0$} atm as maximum $\&$ minimum values of sin $\theta$ is (+1/-1).

The distribution of electrons into orbitals of an atom is called its:

A self – propelled vehicle of mass m, whose engine delivers a constant power P, has an acceleration a = (P/mv). (Assume that there is no friction). In order to increase its velocity from $v_1$ to $v_2$, the distance it has to travel will be:

One body is dropped, while a second body is thrown downward with an initial velocity of $1{\text{ms}}^{-1}$ simultaneously. After what time separation between the two bodies is $18\text{m}$?

For the given uniform square lamina ABCD, whose centre is O,

A cylindrical vessel contains a liquid of density $\rho$ upto a height $h$. The liquid is closed by a piston of mass $m$ and area of cross-section $A$. There is a small hole at the bottom of the vessel. The speed $v$ with which the liquid comes out of the hole is

Three concetric spherical conductor A, B and C of radii R, 2R and 4R respectively. A and C is shorted and B is uniformly charged (charge +Q)

Charge on conductor A is

An archaeologist analysis of the wood in a prehistoric structure reveals that the ratio of ${}^{14}C$to${}^{12}C$ is only one-eighth in the cells in living plants. What is the age of the wood? Given: Half life of ${}^{14}C$ is 5700 years.

For a quadratic equation $a{x}^2+bx+c=0$, if sum of the roots is - 1 and product of the roots is 1, then which of the following holds true?

An isosceles prism of angle ${120}^{\circ }$ has a refractive index $\sqrt{2}$. Two parallel monochromatic rays enter the prism parallel to each other in air as shown. in figure. Find the angle between the emerging rays

The two square faces of a rectangular dielectric slab (dielectric constant 4.0) of dimensions $20cm\times 20cm\times 1.0mm$ are metal-coated. Find the capacitance between the coated surfaces.

Each of the plates shown in figure (31-E19) has surface area $\left(\frac{96}{{\in }_0}\right)\times {10}^{-12}Fm$ on one side and the separation between the consecutive plates is 4.0 mm. The emf of the battery connected is 10 volts. Find the magnitude of the charge supplied by the battery to each of the plates connected to it.

A cylinder is given angular velocity ${\omega }_0$ and kept on a horizontal rough surface. The initial velocity is zero. The distance travelled by it before it starts performing pure rolling is: [Assume radius of cylinder $=R$]

A glass vessel of volume $200{\text{cm}}^3$ is filled with mercury and is heated from ${25}^o\text{C}$ to ${75}^o\text{C}$. What volume of mercury will overflow? Coefficient of linear expansion of glass = $1.8\times {10}^{-6}{/}^o\text{C}$ and coefficient of volumetric expansion of mercury is $1.8\times {10}^{-4}{/}^o\text{C}$.

A horizontal heavy uniform bar of weight W is supported at its ends by two men. At the instant, one of the men lets go off his end of the rod, the other feels the force on his hand changed to

A gas thermometer measures the temperature from the variation of pressure of a sample of gas. If the pressure measured at the melting point of lead is 2.20 times the pressure measured at the triple point of water, find the melting point of lead.

A uniform disc of radius R is put over another uniform disc of radius 2R of the same thickness and density.The peripheries of the two discs touch each other.Locate the centre of mass of the system.

The charge on a conductor is positive Q and its potential is V
(i.e. the electric potential on its surface)
If some more positive charge is added to it, what are the possible values of its new potential?

The efficiency of the Otto cycle is given by which of these expressions?Where r = compression ratio.

Two parallel plate capacitors of capacitances C and 2C are connected in parallel and charged to a potential difference $V_0$. The battery is then disconnected and the region between the plates of the capacitor C is completely filled with a material of dielectric constant 2. The potential difference across the capacitors now becomes: