Explore topic-wise InterviewSolutions in Current Affairs.

A magnetic dipole of magnetic moment $0.72\sqrt{2}$ A $m^2$ is placed horizontally with the north pole pointing towards east. Find the position of the neutral point if the horizontal component of the earth's magnetic field is 18 $\mu$ T.

A rod of negligible heat capacity has length 20 cm, area of cross section 1.0 $c{m}^2$ and thermal conductivity $200W{m}^{-1\circ }{C}^{-1}$. The temperature of one end is maintained at$0^{\circ }C$ and that of the other end is slowly andlineraly varied from $0^{\circ }C$ to ${60}^{\circ }C$ in 10 minutes. Assuming no loss of heat through the sides, find the total heat transmitted throug the rod in these 10 minutes.

Which of the following set of forces
cannot keep a body in equilibrium?

Which of the following wavelength will be absent from the X-ray spectrum if the X-ray tube is operated at 40,000 V?

In the Bohr's hydrogen atom model, the radius of the stationary orbit is directly proportional to (n = principle quantum number)

Paper is an insulator. It gets attracted to the comp through charging by induction. How can this be possible when there are no free electrons on insulators and then how can electrons move and induced charges are formed?

The pressure of 2 moles of ammonia at 27⁰ when its volume is 5 L according to van der WaaL's equation is (Given, α=4.17, b=0.03711)

Two wave pulses travel in opposite directions on a string and approach each other. The shape of one pulse is inverted with respect to the other.

A disc with linear velocity $V$ and angular velocity $\omega$ is placed on the ground.
Suppose $a$ and $\alpha$ be the magnitudes of linear and angular acceleration due to friction. Then match the statements in Column $I$ with statements in column $II$


$\begin{array}{cc}ColumnI& ColumnII\\ \left(A\right)\text{When}V=R\omega & \left(p\right)a=R\alpha (a\ne 0)\\ \text{(B)When}V=\frac{R\omega }{2}& \left(q\right)a>R\alpha \\ \left(C\right)\text{When}V=2R\omega & \left(r\right)a<R\alpha \\ & \left(s\right)\text{None of these}\end{array}$

Two boats $A$ and $B$ are moving along perpendicular paths in a still lake at night. At $t=0$, the boats are $300\text{m}$ apart. If boat $A$ moves with a speed of $3\text{m/s}$ and boat $B$ moves with a speed of $4\text{m/s}$ in a direction such that they can collide after sometime, then the boats will collide after

Magnetic field at point P inside solenoid of n turns per unit length and current i is

A uniform wire of resistance $72\Omega$ is bent in the form of a hexagon (regular), then the effective resistance between A & B is

Three rods each of mass $m$ and length $L$ are joined to form an equilateral triangle as shown in the figure. What is the moment of inertia about an axis passing through the centre of mass of the system and perpendicular to the plane?

In an n – p – n transistor circuit, the collector current is 10 mA. If $90\%$ of the electrons emitted reach the collector. Then

A wooden plank of mass $30\text{kg}$ is resting on a smooth horizontal floor. A man of mass $70\text{kg}$ starts moving from one end of the plank to the other end. The length of plank is $20\text{m}$. Find the displacement of the plank over the floor when the man reaches the other end of the plank.

Degree of freedom of unknown gas is $3$. The gas can be

An equilateral triangular wire frame is made up of three thin uniform rods of mass per unit length $\lambda ,2\lambda$ and $3\lambda$ as shown in figure. Assuming the origin to be at point $\text{O}$, which of the following options is(are) correct regarding the position of $COM$ of system?

The displacement of a body in $8s$ starting from rest with an acceleration of $20cm/s^2$ is

A thin circular ring of mass $M$ and radius $r$ is rotating about its axis with a constant angular velocity $\omega$. Two objects, each of mass $m$ are attached gently to the opposite ends of a diameter of the ring. The ring now rotates with an angular velocity of

The bob of a pendulum at rest is given a sharp hit to impart a horizontal velocity $u$. If $l$ is the length of the pendulum, find the tension in the string when $\theta ={90}^{\circ }$ from the vertical. Given: $u=\sqrt{3gl}$

EM radiations of wavelength 242nm is just sufficent to ionize Sodium atom .Then the ionization energy for sodium in KJ per mole is

a) 492.65 b) 400

c) 247 d) 600

Why is it easier to fetch water from a well using a pulley?

The unit vector perpendicular to both $\hat{i}+\hat{j}$ and $\hat{j}-\hat{k}$ is

A wheel starting from rest is uniformly accelerated at $2{\text{rad/s}}^2$ for 20 seconds. It rotates uniformly for the next 20 seconds and is finally brought to rest in the next 20 seconds. Total angular displacement of the wheel in radians is

Velocity of a boat in still water is $13m/s$. If the water in a river flows with a velocity of $5m/s$ and the width of the river is $156m$, what is the difference in time taken by the boat to cross the river in the shortest possible path and the shortest possible time?

The equation of progressive wave in a wire is given by $y=0.15sin\left[2\pi (15t-\frac{x}{10})\right]$
Where the distance is in meters and time in seconds.
Determine i) amplitude, ii) frequency, iii) wavelength and iv) velocity of the wave

When a particle oscillates simple harmonically,its kinetic energies varies periodically.if frequency of the particle is f,the frequency of the kinetic energy is :

A)f/2 B)f C)2f D)4f

Two identical particles of charge q each are connected by a mass less spring of force constant K. They are placed over a smooth horizontal surface. They are released when the separation between them is r and spring is in its natural length. If maximum extension of the spring is r, the value of $\sqrt{K}$ is (Neglect gravitational effect)

In a two dimensional motion of particle, the particle moves from point Α, position vector ${\overrightarrow{r}}_1$ to point B, position vector ${\overrightarrow{r}}_2$. If the magnitudes of these vectors are, respectively $r_1=3and{r}_2=4$, and the angles they make with the x- axis are ${\theta }_1={75}^{0}and{\theta }_2={15}^0,$ and respectively, then find the magnitude of the displacement vector.

The mass of the three wire of copper are in the ratio 1:3:5, and their lengths are in ratio 5:3:1. The ratio of their electrical resistance is

So in 2D motion does the instantaneous acceleration always have to be along the same line as velocity( either 0 or 180 degrees)?

A block C of mass m is moving with velocity $v_0$ and collides elastically with block A of mass m and connected to another block B of mass 2m through spring with spring constant K. What is the value of K, if $x_0$ is compression of spring, when velocity of A and B is same?

From the previous problem at what angle to the horizontal must be steered in order to reach a point on the opposite bank directly east from the starting point? (Assuming his speed w.r.t. to the river is 4 m/s)

The figure shows a snap shot of a vibrating string at t = 0. The particle P is observed moving up with velocity $20\sqrt{3}$cm/s. The tangent at P makes an angle ${60}^{\circ }$ with x-axis.


The equation of the wave is (in SI units)

A beam of light strikes a piece of glass at an angle of incidence of ${60}^{\circ }$ and the reflected beam is completely plane polarized. The refractive index of the glass is:

The binding energy of deuteron ${(}_1^{2}H)$ is 1.15 MeV per nucleon and an alpha particle ${(}_2^{4}He)$ has a binding energy of 7.1 MeV per nucleon. Then in the reaction

${}_1^{2}H{+}_1^{2}H{\to }_2^{4}He+Q$

the energy Q released is approximately

Figure shows a square current carrying loop ABCD of side 2m and current $I=\frac{1}{2}A$. The magnetic moment $\overrightarrow{M}$ of the loop is:

For gas samples, most probable speed is $800\text{m/s}$. The molecules travelling with speed $799-800\text{m/s}$ are $N_1$, molecules travelling with speed $899-900\text{m/s}$ are $N_2$ and molecules travelling with speed $999-1000\text{m/s}$ are $N_3$, then

Two wires are made of the same material and have the same volume. The first wire has cross-sectional area $A$ and the second wire has cross-sectional area $3A$. If the length of the first wire is increased by $\Delta l$ on applying a force $F$, how much force is needed to stretch the second wire by the same amount ?

A diatomic gas obeys the law $P{V}^x$= constant. For what value of x, it has negative molar specific heat?

Two waves of intensity $I_2$ and $I_2$ interfere. The maximum intensity produced to the minimum intensity is in the ratio $\alpha$. Then,$\frac{I_1}{I_2}$ is equal to

A particle is executing SHM. Find the phase constants of the particle, when it starts from the points $\text{A},\text{B}$ and $\text{C}$ respectively as shown below.
(Phase constant $\varphi$ is the range of $[0,2\pi ]$)

A small bead of mass $m=1\text{kg}$ is carried by a circular hoop having centre at $C$ and radius $r=1\text{m}$ which rotates about a fixed vertical axis (as shown). The coefficient of friction between bead and hoop is $\mu =0.5$. The maximum angular speed of the hoop in $\text{rad/s}$ for which the bead does not have relative motion with respect to hoop: initial position of bead is shown in figure. Answer upto 2 decimal places.

Block $A$ of mass $\frac{m}{2}$ is connected to one end of a light rope which passes over a light frictionless pulley as shown in figure.


A man of mass $2m$ climbs the other end of the rope with a relative acceleration of $\frac{g}{2}$ with respect to rope. Find the acceleration ($a_0$) of block $A$ with respect to ground.