Explore topic-wise InterviewSolutions in Current Affairs.

Give a daily life example of the statement : Two bodies having same quantity of heat may differ in their temperature and the vice versa.

In a YDSE, light of wavelength $\lambda =5000\stackrel{\circ }{A}$ is used, which emerges in phase from two slits a distance $d=3\times {10}^{-7}m$ apart. A transparent sheet of thickness $t=1.5\times {10}^{-7}m$, refractive index $n=1.17$, is placed over one of the slits. Where does the central maxima of the interference now appear from the center of the screen? (Find the value of y?)

A rod 1 m long and made of material of thermal conductivity 420 W/m/K has one of its ends in melting ice and the other end in boiling water. If its area of cross-section is 10 $c{m}^2$, the amount of ice that melts in 1 minute is

The radii of circular orbits of two satellites $A$ and $B$ of the earth are $4R$ and $R$ respectively. If the speed of satellite $A$ is $3v$, then the speed of satellite $B$ will be

A block of mass $m$ is placed on a wedge. The wedge can be accelerated in four manners marked as $\left(1\right),\left(2\right),\left(3\right)$ and $\left(4\right)$. If the normal reactions (on $m$) in situation $\left(1\right),\left(2\right),\left(3\right)$ and $\left(4\right)$ are $N_1,N_2,N_3\text{and}{N}_4$ respectively and acceleration with which the block slides with respect to the wedge in situations are $b_1,b_2,b_3\text{and}{b}_4$ respectively, then $(\text{Given}a=\frac{g}{2}m{s}^{-2})$

If the incident ray is stationary, but the plane mirror rotates by an angle of ${30}^{\circ }$, then the reflected ray gets rotated by .

A long string having a cross-sectional area $0.8{\text{mm}}^2$ and density $12.5{\text{g/cm}}^3$, is subjected to a tension of $64\text{N}$ along the $x-$ axis . One end of this string is attached to a vibrator, which is vibrating in a transverse direction. Find the speed of the wave travelling on the string.

If a particle has velocity $v\left(t\right)=18-6t\text{m/s}$, the magnitude of average velocity in $10\text{sec}$ is

If a gas is taken from $A$ to $C$ through $B$, then heat absorbed by the gas is $8\text{J}$. Heat absorbed by the gas in taking it directly from $A$ to $C$ is

A frictionless track $ABCDE$ ends in a circular loop of radius $R$. A body slides down the track from point $A$ which is at height $h=5\text{cm}$. Find the maximum value of $R$ for which the body completes the loop successfully.

WHAT IS minimum number of vectors of unequal of unequal magnitudes to produce 0 vector?

From the given plot between Z and P , which of the following statements are correct for a real gas?

A force $F=(3\hat{i}+c\hat{j}+2\hat{k})\text{N}$ acting on a particle causes a displacement of $\overrightarrow{S}=(-4\hat{i}+2\hat{j}-3\hat{k})\text{m}$. If the work done is $6\text{J}$, then the value of ${}^{\prime }{c}^{\prime }$ is

Two charges $q_1$ and $q_2$ are placed $30\text{cm}$ apart, as shown in the figure. A third charge $q_3$ is moved along the arc of a circle of radius $40\text{cm}$ from $C$ to $D$. The change in the potential energy of the system is $\frac{q_3}{4\pi {ϵ}_0}k$, where $k$ is

A body rotating at $20\text{rad/s}$ is acted upon by a uniform torque providing it an angular deceleration of $2{\text{rad/s}}^2$. After what time will the body have the same kinetic energy as the initial value, if the torque acts continuously?

The average thermal energy of a helium atom at the temperature of the sun (T=6000k)

Consider the situation shown in figure. What are the signs of $q_{1}and{q}_2$?

A string of length $10\text{cm}$ fixed at one end and free at another end, has its fundamental frequency half that of second overtone for another string fixed at both ends. What will be the length of string fixed at both ends?
(Assume velocity of wave in both strings is same)

The displacement $x$ of a particle along a straight line at time $t$ is given by $x=a_0+a_{1}t+a_2{t}^3$. The acceleration $a$ of the particle at time $t=5$ is

Two particles A and B are moving with uniform velocity as shown in the figure given below at t =0.

Find out shortest distance between two particles.

The equation of trajectory of a projectile is $y=(\frac{x}{\sqrt{3}}-\frac{g{x}^2}{20})$, where $x$ and $y$ are in meter. The maximum range of the projectile is (take $g=10m/s^2$)

A flask of volume $V$ contains some mercury. It is found that at different temperatures, the volume of air inside the flask remains the same. If ${\gamma }_g$ and ${\gamma }_m$ are the coefficients of cubical expansion of glass and mercury respectively, the volume of mercury in the flask is

The walls of the halls built for music concerts should

A closed system receives $200\text{kJ}$ of heat at constant volume. It then rejects $100\text{kJ}$ of heat while it has $50\text{kJ}$ of work done on it at constant pressure. If an adiabatic process can be found which will restore the system to its initial state, the work done by the system during this process is

The kinetic energy of a particle executing S.H.M. is 16 J when it is in its mean position. If the amplitude of oscillations is 25 cm and the mass of the particle is 5.12 kg, the time period of its oscillation is

[Haryana CEE 1996; AFMC 1998]

A block of mass 2 kg hangs from the rim of a wheel of radius 0.5 m. On releasing 2 kg from rest the block falls through 5 m height in 2 s. The moment of inertia of the wheel will be

From a circular disc of radius R and mass 9M, a small disc of radius R/3 is removed from the disc. The moment of inertia of the remaining disc about an axis perpendicular to the plane of the disc and passing through O is

The displacement-time graph for two particles A and B are straight lines inclined at angles of ${30}^{\circ }$ and ${60}^{\circ }$ with the time axis. The ratio of velocities of $V_A$ : $V_B$ is

A drop of liquid of radius $R={10}^{-2}m$ having surface tension $S=\frac{0.1}{4\pi }N{m}^{-1}$ divides itself into $K$ identical drops. In this process the total change in the surface energy $\Delta U={10}^{-3}J$. If $K={10}^{\alpha }$ then the value of $\alpha$ is

The maximum velocity and the maximum acceleration of a body moving in a

simple harmonic oscillator are 2 m/s and 4 m/$s^2$. Then angular velocity will be

[Pb. PMT 1998; MH CET 1999, 2003]

I have an insulator with dielectric constant k. If I place it in a region in vacuum with a field E. Then the net field inside the dielectric will be?

A body of mass 5 kg is moving along the x-axis with a velocity 2$m{s}^{-1}$. Another body of mass 10 kg is moving along the y-axis with a velocity $\sqrt{3}m{s}^{-1}$. They collide at the origin and stick together. The final velocity of the combined mass is

A wave is travelling in string 1 with velocity $v_1$. It is then both reflected and transmitted from a joint to string 2 where the velocity is $v_2$. If $A_i$ represents the incident amplitude, What are the reflected and transmitted amplitudes?

The sound level at a point is increased by 30 dB. By what factor is the pressure amplitude increased?

A stationary cylinder of oxygen used in a hospital has the following characteristics at room temperature $300K$, gauge pressure $1.38\times {10}^{7}Pa$, volume $16L$. If the flow rate, measured at atmospheric pressure, is constant at $2.4L/min$, the cylinder will last for nearly

A particle is dropped from point $P$ at time $t=0$. At the same time, another particle is thrown from the point $O$ as shown. It collides with the particle $P$, $2\text{sec}$ after they start. The value of $V_0$ (in m/s) is (Point $O$ is not necessarily on the ground)

A ball is released from height $h$ and another ball from height $2h$. The ratio of time taken by the two balls to reach the ground is

(a) Define self-inductance of a coil. Obtain an expression for the energy stored in a solenoid of self-inductance ‘L’ when the current though it grows from zero to ‘I’.

(b) A square loop MNOP of side 20 cm is placed horizontally in a uniform magnetic field acting vertically downwards as shown in the figure. The loop is pulled with a constant velocity of 20 cm $s^{-1}$ till it goes out of the field.

(i) Depict the direction of the induced current in the loop as it goes out of the field. For how long would the current in the loop persist?

(ii) Plot a graph showing the variation of magnetic flux and induced emf as a function of time.

OR

(a) Draw the magnetic field lines due to a circular loop area $\overrightarrow{A}$ carrying current I. Show that it acts as a bar magnet of magnetic moment $\overrightarrow{m}=I\overrightarrow{A}$

(b) Derive the expression for the magnetic field due to a solenoid of length ‘2l’, radius‘a’having ’n’ number of turns per unit length and carrying a steady current ‘I’ at a point on the axial line, distance ‘r’ from the centre of the solenoid. How does this expression compare with the axial magnetic field due to a bar magnet of magnetic moment ‘m’?

A body of mass $m$ is attached to the lower end of a spring whose upper end is fixed. The spring has negligible mass. When the mass $m$ is slightly pulled down and released, it oscillates with a time period of $3s$. When the mass $m$ is increased by $1kg$, the time period of oscillations becomes $5s$. The value of $m$ in $kg$ is