Explore topic-wise InterviewSolutions in Current Affairs.

A metre scale is made up of steel and measures correct length at ${16}^{\circ }C$. What will be the percentage error if this scale is used (a) on a summer day when the temperature is ${46}^{\circ }C$ and (b) on a winter day when the temperature is $6^{\circ }C$ ? Coefficient of linear expansion of steel $=11\times {10}^{-6}{}^{\circ }{C}^{-1}$

A vessel contains $N$ molecules of a gas at temperature $T$. Now the number of molecules is doubled, keeping the total energy in the vessel constant. The temperature of the gas is.

Three identical particles are joined together by a thread as shown in figure. All the three particles are moving in a horizontal plane. If the velocity of the outermost particle is $v_0$, then the ratio of tensions in the three sections of the string is

An aluminium vessel of mass 0.5 kg contains 0.2 kg of water at ${20}^{\circ }C$. A block of iron of mass 0.2 kg at ${100}^{\circ }C$ is gently put into the water. Find the equilibrium temperature of the mixture. Specific heat capacities of aluminium, iron and water are $910K{g}^{-1}{K}^{-1}470Jk{g}^{-1}{K}^{-1}$ and $4200Jk{g}^{-1}{K}^{-1}$ respectively.

Three rods made of the same material and having the same cross section have been joined as shown in the figure. Each rod is of the same length. The left and right ends are kept at $0^{o}Cand{90}^{o}C$ respectively .R is thermal resistance of each road. The temperature of the junction of the three rods will be

Calculate the heat absorbed by a system in going through the cyclic process shown in figure.

A transverse wave described by

$y=\left(0.02m\right)sin\left[\right(1.0m^{-1})x+(30s^{-1}\left)t\right]$

propagates on a stretched string having a linear mass density of $1.2\times {10}^{-4}kg{m}^{-1}$. Find the tension in the string.

A steel rod of length 1 m rests on a smooth horizontal base. If it is heated from $0^{\circ }C$ to ${100}^{\circ }C$, what is the longitudinal strain developed ?

A projectile of mass $m$ is fired with a velocity $u$ from a point $P$ as shown. Neglecting air resistance, find the magnitude of the change in momentum of the projectile between the points $P$ and $Q$.

An automobile moves on a road with a speed of $54km{h}^{-1}$. The radius of its wheel is $0.45m$ and the moment of inertia of the wheel about its axis of rotation is $3kg{m}^2$. If the vehicle is brought to rest in $15s$, the magnitude of average torque applied by its brakes to the wheels is

The maximum speed of a particle executing SHM is $1m{s}^{-1}$ and maximum acceleration is $1.57m{s}^{-2}$. Its frequency is

In the equation Rate = Z_AB.e^-E_a^/RT, Z_AB is:

The ratio of acceleration due to gravity at a depth (h) below the surface of earth and at a height above the surface of earth for h << $R_e$( radius of earth ):

If the critical angle for TIR from medium to vacuum is ${30}^{\circ },$ the velocity of light in medium is:

In a Young's double slit experiment, slits are separated by $0.5mm$, and the screen is placed $150cm$ away. A beam of light consisting of two wavelengths, $650nm$ and $520nm$, is used to obtain interference fringes on the screen. The least distance from the common central maximum to the point where the bright fringes due to both the wavelengths coincide is

The inward and outward electric flux from a closed surface are respectively $8\times {10}^3$ and $4\times {10}^3$ units. Then the net charge inside the closed surface is

When forces $F_1,F_2$ and $F_3$ are acting on a particle of mass m such that $F_2$ and $F_3$ are mutually perpendicular, then the particle remains stationary. If the force $F_1$ is now removed then the acceleration of the particle is

A toy car of mass $5\text{kg}$ moves up a ramp under the influence of force F plotted against displacement $x$. The maximum height attained is given by

Consider $g=10{\text{ms}}^{-2}$ and $F$ ceases to act as the car reaches $x=11\text{m}$

Transverse waves travel with a speed of $40\text{m/s}$ in a string under a tension of $12\text{N}$. What tension is required for a wave speed of $60\text{m/s}$ in the same string?

The simple pendulum of mass $2\text{kg}$ is released from rest in the horizontal position. As it reaches the bottom position, the cord wraps around the smooth fixed pin at $B$ and continues on the smaller arc in the vertical plane. Calculate the magnitude of the force $R$ supported by the pin at $B$ when the pendulum passes the position.
[Take $g=9.8{\text{m/s}}^2$]

In the $CGS$ system of units, the magnitude of the force is $100\text{dyne}$. If in another system of units, the fundamental physical quantities like mass, length and time are expressed in kilogram, metre and minute respectively, the magnitude of the force in this system of units is

A man throws a ball of mass $m$ on a vertical wall with speed $v$. If the ball bounces back with the same speed, find out the magnitude of impulse on the ball, imparted by normal reaction from the wall.

The bob of a pendulum at rest is given an impulse to impart a horizontal velocity $\sqrt{gl}\text{m/s}$ where $l$ is the length of the pendulum. Find the tangential acceleration at the point where velocity of the bob is zero.

A track consists of two circular parts ABC and CDE of equal radius 100 m and joined smoothly as shown in figure. Each part subtends a right angle at its centre. A cycle weighing 100 kg together with the rider travels at a constant speed of 18 km/hr on the track. What should be the minimum friction coefficient between the road and the tyre, which will ensure that the cyclist can move with constant speed? Take g = 10 m/s²

A $10\text{cm}$ long wire is placed horizontal on the surface of water and is gently pulled up with a force of $2\times {10}^{-2}\text{N}$ to keep the wire in equilibrium. The surface tension (in ${\text{Nm}}^{-1}$) of water is

A ball of mass $m=0.5\text{kg}$ is attached to the end of a string having length $l=0.5\text{m}$. The ball is rotated on a horizontal circular path about the vertical axis, as shown in figure. The maximum tension that the string can bear is $324\text{N}$. Then, maximum possible value of angular speed of ball (in $\text{rad/s}$) will be:

Two cells of emfs $E_1$ and $E_2(E_1>E_2)$ are connected as shown in fig.


When a potentiometer is connected between $A$ and $B$, the balancing length of the potentiometer wire is $300\text{cm}$. On connecting the same potentiometer between $A$ and $C$, the balancing length is $100\text{cm}$. The ratio $\frac{E_1}{E_2}$ is

Kinetic energy $\left(\text{in joule}\right)$ in one wave length of transverse wave is twice of its average kinetic energy per unit length The wave length of the transverse wave is

If potential (in volts) in a region is expressed as $V(x,y,z)=6xy-y+2yz$, the electric field $\left(\frac{N}{C}\right)$ at point $(1,1,0)$ is

Position of a particle in a rectangular-co-ordinate system is (3, 2, 5). Then its position vector will be

A student is standing at a distance of 50 metres from a bus. As soon as the bus begins its motion (starts moving away from student) with an acceleration of 1 m s${}^{-2}$, the student starts running towards the bus with a uniform velocity u. Assuming the motion to be along a straight road, the minimum value of u, so that the student is able to catch the bus is:

A car and a truck move in the same straight line at the same instant of time from the same place. The car moves with a constant velocity of $40m/s$ and the truck starts with a constant acceleration of $4m/s^2$. Find the time $t$ that elapses before the truck catches up with the car.

Block $A$ and $B$ in the figure are connected by a bar of negligible weight. If $A=B=170\text{kg}$ and ${\mu }_A=0.2$ and ${\mu }_B=0.4$, where ${\mu }_A$ and ${\mu }_B$ are the coefficients of limiting friction between the blocks and the plane, calculate the contact force on the bar due to $A$ $(g=10{\text{m/s}}^2)$

A capacitor with stored energy 4.0 J is connected with an identical capacitor with no electric field in between. Find the total energy stored in the two capacitors.

An isolated smooth ring of mass M = 2m with two small beads each of mass m is as shown in the figure. Initially both the beads are at diametrically opposite points and have velocity $V_0$ (for each) in same direction. The speed of the beads just before they collide for the first time is (complete system is placed on a smooth horizontal surface and assume each point of ring is touching the surface)

In the Column I below, four different paths of a particle are given as functions of time.
In these functions, $\alpha$ and $\beta$ are positive constants of appropriate dimensions and $\alpha \ne \beta .$ In each case, the force acting on the particle is either zero or conservative.
In Column II, five physical quantities of the particle are mentioned: $\overrightarrow{p}$ is the linear momentum $\overrightarrow{L}$ is the angular momentum about the origin, $K$ is the kinetic energy, $U$ is the potential energy and $E$ is the total energy.
Match each path in Column I with those quantitites in Column II, which are conserved for that path.
$\begin{array}{cc}\text{Column~I}& \text{Column~II}\\ \left(A\right)\overrightarrow{r}\left(t\right)=\alpha t\hat{i}+\beta t\hat{j}& 1.\overrightarrow{p}\\ \left(B\right)\overrightarrow{r}\left(t\right)=\alpha \cos \omega t\hat{i}+\beta \sin \omega t\hat{j}& 2.\overrightarrow{L}\\ \left(C\right)\overrightarrow{r}\left(t\right)=\alpha (\cos \omega \hat{i}+\sin \omega t\hat{j})& 3.K\\ \left(D\right)\overrightarrow{r}\left(t\right)=\alpha t\hat{i}+\frac{\beta }{2}{t}^2\hat{j}& 4.U\\ & 5.E\end{array}$

If we put a ball from a height of 5m,how the displacement will be -5

Explain burrowing movement in explain.

A long, straight wire carrying a current of 1.0 A. is placed horizontally in a uniform magnetic field $B=1.0\times {10}^{-5}T$ pointing vertically upward (figure 35-E1). Find the magnitude of the resultant magnetic field at the points P and Q, both situated at a distance of 2.0 cm from the wire in the same horizontal plane.

Why do we treat air and vacuum similarly?Eg:The permittivity of air and vacuum is same

What is hysteresis?