Explore topic-wise InterviewSolutions in Current Affairs.

A planet of small mass $m$ moves around the Sun of mass $M$ along an elliptical orbit such that its minimum and maximum distances from sun are $r$ and $R$ respectively. Its period of revolution will be:

A knife-edge divides a sonometer wire into two parts. The fundamental frequencies of the two parts are $v_1$ and $v_2$. The fundamental frequency of the sonometer wire when the knife-edge is removed will be

A convex lens of focal length $10\text{cm}$ is placed $30\text{cm}$ in front of a second convex lens also of the same focal length. A plane mirror is placed after the two lenses. Where should a point object be placed in front of the first lens so that it images on to itself ?

Three identical springs of force constant $100\text{N/m}$ attached to mass as shown in figure.





Calculate the time period of oscillation after a small displacement of mass $m=1\text{kg}$ towards spring $3.$

Two coherent light sources, each of wavelength $\lambda$, are separated by a distance of $3\lambda$. The maximum number of minima formed on the line $\text{AB}$, which runs from $-\infty$ to $+\infty$, is

A free hydrogen atom after absorbing a photon of wavelength ${\lambda }_a$ gets excited from the state $n=1$ to the state $n=4$. Immediately after that the electron jumps to n = m state by emitting a photon of wavelength ${\lambda }_e$. Let the change in momentum of atom due to the absorption and the emission are $\Delta P_a$ and $\Delta P_e$ respectively. If ${\lambda }_a/{\lambda }_e=1/5$, which of the option (s) is/are correct ?

[Use $hc=1242eV$ nm ; $1nm={10}^{-9}m$, h and c are Plank's constant and speed of light, respectively]

Let $\overrightarrow{a}=2\hat{i}-\hat{j}+\hat{k},\overrightarrow{b}=\hat{i}+2\hat{j}-\hat{k}$ and $\overrightarrow{c}=\hat{i}+\hat{j}-2\hat{k}$ be three vectors. A vector in the plane of $\overrightarrow{b}$ and $\overrightarrow{c}$ whose projection on $\overrightarrow{a}$ is of magnitude $\sqrt{\frac{2}{3}}$ can be

Mr. Sharma goes for jogging every morning in a circular park whose circumference is 1 km. He makes 3 complete circles in 5 minutes (Approximately as fast as bolt). Find his average velocity.

A $50\text{kg}$ skydiver falls through the air and attains terminal velocity after some time. The drag force is a function of velocity given as $F_{\text{drag}}=-b{v}^2$ where the negative sign denotes that the drag force is opposite to the direction of velocity. What is the terminal velocity of the skydiver (assuming the drag constant $b$ is $0.2\text{kg/m})$?

Two sources P and Q produces notes of frequency $990\text{Hz}$ each. A listener moves from P to Q with a speed of $1{\text{ms}}^{-1}$. If the speed of sound is $330\text{m/s}$, then the number of beats heard by the listener per second is

A magnetic field $B=1.5t\text{T}$ exists in a cylindrical region of radius $R=25\text{cm}$ as shown in the figure. What will be the magnitude of the induced electric field at a distance of $0.2\text{m}$ from the axis of the cylinder ?

Consider two charged metallic spheres $S_1\text{and}{S}_2$ of radii $R_1\text{and}{R}_2$, respectively. The electric fields $E_1\left(\text{on}{S}_1\right)\text{and}{E}_2\left(\text{on}{S}_2\right)$ on their surfaces are such that $E_1/E_2=R_1/R_2$. Then the ratio $\frac{V_1\left(\text{on}{S}_1\right)}{V_2\left(\text{on}{S}_2\right)}$ of the electrostatic potentials on each sphere is:

Energy required in very slowly moving a body of mass $m$ from a distance $2R$ to $3R$ (where $R$ is radius of earth) from centre of earth of mass $M$ is

Two concentric spherical shells are separated by vacuum. The inner shell has total change $Q$ and radius $r$. The outer shell has total charge $-Q$ and radius $2r$. The potential energy stored in the capacitor is

The bob of a simple pendulum is displaced from its equilibrium position $O$ to a position $Q$, which is at height $h$ above $O$ and the bob is then released. Assuming the mass of the bob to be $m$ and time period of oscillations to be $2\text{s}$, the tension in the string, when the bob passes through $O$ is

The saturation vapour pressure of water at 100°C is

Choose the correct statement. When the temperature of an ideal gas is increased

Two wires A and B are formed from the same material and same mass. Diameter of B is twice of A. If the resistance of wire A is 32 ohm.. find the resistance of wire B!

A body is projected with velocity $u$ at an angle $\theta$ with the horizontal. Another body having double mass is also projected with the same velocity but at an angle $90-\theta$. The ratio of their maximum heights is

The upper stratosphere consisting of the ozone layer protects us from the sun's radiation that falls in the wavelength region of :

A toroid having a square cross-section of side $5\text{cm}$ and inner radius of $15\text{cm}$, has $500$ turns and carries a current of $0.8\text{A}$. What is the magnetic field just inside the outer radius of the toroid ?

Find the second order
derivatives of the function.

A body is thrown vertically upward such that the distance travelled by it in fifth and sixth second are equal .the maximum height reached by body is

If mass is uniformly distributed, find the distance $\left(\text{in m}\right)$ of the centre of mass of the T-shaped plate from point $O$.

The lower surface of a cube is fixed. On its upper surface, force is applied at an angle of 30° from its surface. The change will be of the type

A particle is projected from the bottom of an inclined plane of inclination ${30}^{\circ }$ (with the horizontal) with speed $40\text{m/s}$ at an angle ${60}^{\circ }$ with the horizontal. The speed of the particle when its velocity vector is parallel to inclined plane is $(g=10{\text{m/s}}^2)$

Which of the following is true for a step up transformer?