Explore topic-wise InterviewSolutions in Current Affairs.

A body is displaced from $\overrightarrow{r_A}=(2\hat{i}+4\hat{j}-2\hat{k})\text{m}\text{to}\overrightarrow{r_B}=(8\hat{i}+14\hat{j}+6\hat{k})\text{m}$ under the action of a constant force $\overrightarrow{F}=(2\hat{i}+3\hat{j}+6\hat{k})\text{N}$.
If the initial kinetic energy of the body is $15\text{J}$, Find the kinetic energy of the body at the end of displacement.

A rocket is going towards moon with a speed $v$. The astronaut in the rocket sends a signal of frequency $f$ towards moon and receives it back on reflection from moon. What will be the frequency of the signal received by the astronaut? $(\text{Take}v<<<c)$

Two identical rods each of mass 'M' and length 'l' are joined in crossed position. The moment of inertia of this system about a bisector is.

The vector $\overrightarrow{P}=a\hat{i}+a\hat{j}+3\hat{k}\text{and}\overrightarrow{Q}=a\hat{i}-2\hat{j}-\hat{k}$ are perpendicular to each other. The positive value of $a$ is

When a surface of thickness 1 $cm$ is illuminated with light of wavelength $\lambda$, the stopping potential is $V$. When the same surface is illuminated by light of wavelength $2\lambda$, the stopping potential is $\frac{V}{3}$. Then the threshold wavelength for the surface is:

If force f length L current I and time t are taken as the basic quantities find the dimension of E_o.

A man is inside a lift. When the lift is moving up with certain acceleration, the apparent change in weight is $25\%$. When the lift moves down with double the acceleration, the apparent change in weight is

Three plates $P,Q,R$ each of area $A$ have separation $d$ between $P$ and $Q$ and also between $Q$ and $R$. The energy stored when the plates are fully charged is:-

Two charged particles are moving parallel to each other with velocity $v$ at a finite distance $d$. If these two particles have identical charges $q$ on them , then what is the ratio of magnetic force to electric force between two charges? ($c$ is speed of light$={\mu }_0{\epsilon }_0$)

टका पुराने ज़माने का सिक्का था। अगर आजकल सब चीज़ें एक रुपया किलो मिलने लगें तो उससे किस तरह के फ़ायदे और नुकसान होंगे?

Curl of vector $overrightarrowF=x^2{z}^2\hat{i}-2x{y}^{2}z\hat{j}+2y^2{z}^3\hat{k}$

Two person $A$ and $B$ start running from same initial point and in same direction along a circular path with speed of $5\text{km/hr}$ and $2\text{km/hr}$ respectively. If the length of circular path is $24\text{km}$, after what time they will meet again?

n identical cells are joined in series with its two cells A and B in the loop with reversed polarities. Emf of each cell is E and internal resistance r. The potential difference across cell A or B is (Here n > 4)

If ${\omega }_1,{\omega }_2$ and ${\omega }_3$ represent the work done in moving a particle from A to B along three different paths 1, 2, and 3 respectively in the presence of a gravitational field, then find the correct relation between ${\omega }_1,{\omega }_2$ and ${\omega }_3$.

What is air pressure?

The two rods shown in figure have identical geometrical dimensions and are made of different materials. They are in contact with two heat baths at temperatures ${100}^{\circ }\text{C}$ and $0^{\circ }\text{C}$. The temperature of the junction is ${70}^{\circ }\text{C}$. Find the temperature of the junction if the rods are interchanged.

A block of mass 10 kg, moving in x direction with a constant speed of 10 $m{s}^{-1}$ , is subjected to a retarding force F = 0.1 x J/m during its travel from x = 20 m to 30 m. It's final KE will be :

How fast do charges travel? What is the speed of charges?

SI unit of wave velocity is:

A wheel completes 2000 revolutions to cover the 9.5 km. distance. then the diameter of the wheel is

The exhaust velocity of the gases coming out of a rocket is $350\text{m/s}$ w.r.t the rocket. The rocket can burn fuel at a rate of $80\text{kg/s}$. For a successful launch, the desired acceleration of the rocket is $4{\text{m/s}}^2$. What is the initial total mass of this rocket? (Take $g=10{\text{m/s}}^2$)

Find the maximum kinetic energy of the photoelectrons ejected when light of wavelength 350 nm is incident on a cesium surface. Work function of cesium = 1.9 eV.

Calculate the frequency and wavelength of photons with energy 3.98 x 10^-15 J.

Which element is best suited for target material in production of X-rays?



$Z$ is the atomic number.



$Z_A=13,Z_B=15,Z_C=20,Z_D=50$

The coordinates of a moving particle at any time ${}^{\prime }{t}^{\prime }$ are given by $x=t^3$ and $y=4t^2$, where $x$ and $y$ are in metre and $t$ in second. The acceleration of the particle at time $t=1s$ is given by