Explore topic-wise InterviewSolutions in Current Affairs.

Three components of sinusoidal progressive waves travelling in the same direction along the same path having the same period, but with amplitudes are $A,A/2$ and $A/3$. The phase of the variation at any position $x$ on their path at time $t=0$ are $0,-\pi /2$ and $\pi$ respectively. Find the amplitude and phase of the resultant wave

Let $\overrightarrow{a}=12\hat{i}+n\hat{j}$ and $|\overrightarrow{a}|=13,$ then the value of $n$ is

The earth’s
surface has a negative surface charge density of 10⁻⁹
C m⁻². The potential difference of 400 kV between
the top of the atmosphere and the surface results (due to the low
conductivity of the lower atmosphere) in a current of only 1800 A
over the entire globe. If there were no mechanism of sustaining
atmospheric electric field, how much time (roughly) would be required
to neutralise the earth’s surface? (This never happens in
practice because there is a mechanism to replenish electric charges,
namely the continual thunderstorms and lightning in different parts
of the globe). (Radius of earth = 6.37 × 10⁶
m.)

A force is acting on a body of mass $3\text{kg}$ kept on a rough horizontal surface. If a friction force of $40\text{N}$ is required to keep the body at rest under the action of this external force. Then find the contact force acting on the body. $(g=10{\text{m/s}}^2)$

A metal frame $PQRS$ having resistance $2\Omega$, where $PQ=QR=RS=15\text{cm}$ and resistance $2\Omega$ is moved with a speed of $5{\text{cm s}}^{-1}$ in a uniform magnetic field $B=2\text{T}$ which is perpendicular to the plane of the frame as shown in figure. The frame is connected to a network of resistance as shown. Find the current induced in the frame.

A gun fires a shell and recoils horizontally. if the shell travels along the barrel with speed $v$, the ratio of speeds with which the gun recoils, if the barrel is (i) horizontal (ii) inclined at an angle of ${30}^{\circ }$ with horizontal, is

A time dependent force $F=6t$ acts on a particle of mass $1kg$. If the particle starts from rest, the work done by the force during the first 1 sec will be

An object is tossed vertically into the air with an initial velocity of $8\text{m/s}$. Using the sign convertion upwards as positive, how does the vertical component of the acceleration $a_y$ of the object (after leaving the hand) vary during the flight of the object?

The potential energy for a force field $\overline{F}$ is given by $\cup$(x,y) = cos(x+y). The force acting on a particle at position given by coordinates (0, $\pi$/4) is

In a fission process, nucleus $A$ divides into two nuclei $B$ and $C$, their binding energies being $E_a,E_b$ and $E_c$ respectively. Then

A rigid body of mass $m$ and radius $R$ rolls without slipping on a rough surface. A force $F$ is acting on it at $x$ distance from the center, as shown in the figure. Find the value of $x$ so that the static friction is zero.



$a$ is linear acceleration, $\alpha$ is angular acceleration and $I_{com}$ is the rotational inertia of the body about its COM.

A $60kg$ body is pushed with just enough force to start it moving across a floor and the same force continues to act afterwards. The coefficients of static friction and sliding friction are $0.5$ and $0.4$ respectively. The acceleration of the body is
(Take $g=10m/s^2$)

1. 20

The difference in angular momentum associated with the electron in two successive orbits of hydrogen atom is:

A current, $i=3.36(1+2t){10}^{-2}\text{A}$ increases at a steady rate in a long straight wire. A small circular loop of radius ${10}^{-3}\text{m}$ has its plane parallel to the wire and is placed at a distance of $1\text{m}$ from the wire. The resistance of the loop is $8.4\times {10}^{-4}\Omega$. Find the magnitude of induced current in the loop.

The equation of state of a gas is given by $(P+\frac{a{T}^2}{V})V^c=(RT+b),$ where a, b, c and R are constants. The isotherms can be represented by $P=A{V}^m-B{V}^m$ , where A and B depend only on temperature then

Explain the meaning of the statement 'electric charge of a body is quantized'.

Why can one ignore qunatization of electric charge when dealing with macroscopic, i.e., large scale charges?

Two vertical plane mirrors are inclined at an angle of with each other.

A ray of light travelling horizontally is reflected first from one mirror and then

from the other. The resultant deviation is

A hollow wooden cylinder of height $h$, inner radius $R$ and outer radius $2R$ is placed in a cylindrical container of radius $3R$. When water is poured into the container, the minimum height $H$ of the container for which cylinder can float inside freely is

Find the nature of the graph of the following quadratic equation in terms of which side it will open.

1. 199.25

In the circuit shown in the figure, the input signal is $v_i\left(t\right)=5+3cos\omega t$



The steady state output is expressed as $v_0\left(t\right)=P+Qcos(\omega t-\varphi ).$ If $\omega CR=2$, the values of P and Q are

The value of the integral $\int \frac{dx}{3\sin x+4\cos x}$

(where $C$ is integration constant)

Why is chromium electroplated on various objects?

Which state of triply ionized Beryllium $\left(B{e}^{+++}\right)$ has the same orbital radius as that of the ground state of hydrogen?

The current $i$ in a coil varies with time $t$ according to the graph shown below. Which of the following graphs, shows the induced emf $\left(E\right)$ in the coil with time?







$[$0.77 Mark$]$

Write the truth table
for a NAND gate connected as given in Fig. 14.45.

Hence identify the
exact logic operation carried out by this circuit.

According to professor Einstein Light shows both particles and wave like behaviour but we know in vacuum sounds can't travel as their is no particles then what behaviour does light shows in vacuum?

The coefficient of self inductance of a solenoid is $0.18\text{mH}$. If a rod of soft iron, of relative permeability $900$, is inserted in it, the coefficient of self inductance will become -

The PN junction diode is used as

A solid sphere of mass $5\text{kg}$ and radius $1\text{m}$ is kept on a rough surface. A force $F=30\text{N}$ is acting at the top most point. Friction required for pure rolling is

Let $\overrightarrow{v}$ be a vector in the plane such that $|\overrightarrow{v}-\overrightarrow{i}|=|\overrightarrow{v}-2\overrightarrow{i}|=|\overrightarrow{v}-\overrightarrow{j}|$. Then $|\overrightarrow{v}|$ lies in the interval

According to the Snell's Law of Refraction:

Mr. X works in a store which sells tyres. One cold evening when Mr. X was working alone, he accidentally got locked in the basement where all the tyres were stored. Since no one could help him till the next morning, he wanted to somehow warm the basement. To do so he decided that he will burst the tyres which (filled with air), causing explosions, which he thought will release hot air, and keep him warm.

Will Mr.X's idea work?