Explore topic-wise InterviewSolutions in Current Affairs.

If two waves, originating from sources represented by $y_1=4\sin \left(\omega t\right)$ and $y_2=3\sin (\omega t+\frac{\pi }{3})$ interfere at a point. The amplitude of that point will be about,

Four
point charges q_A
= 2 μC, q_B
= −5 μC, q_C
= 2 μC, and q_D
= −5
μC are located at the corners of a square ABCD of side 10 cm. What
is the force on a charge of 1 μC placed at the centre of the
square?

When $100\text{V}DC$ is applied across a solenoid, a current of $1\text{A}$ flows in it. When $100\text{V}AC$ is applied across the same coil, current drops to $0.5\text{A}.$ If the frequency of the $AC$ source is $50\text{Hz},$ the impedance and inductance of the solenoid are,

Two capacitors of capacitance $1\mu \text{F}$ and $2\mu \text{F}$ are charged to potential difference $20\text{V}$ and $15\text{V}$ as shown in figure. If now terminal $\text{B}$ and $\text{C}$ are connected together while terminal $\text{A}$ is connected with positive terminal of battery and terminal $\text{D}$ of capacitor connected with negative terminal of battery with an emf $30\text{V}$.





The final charges on $1\mu \text{F}$ and $2\mu \text{F}$ capacitors respectively will be;

A torch bulb rated as $4.5W-1.5V$ is connected as shown in the figure. The emf of the cell needed to make the bulb glow at full intensity is

A ball is thrown upwards with an initial velocity $v_0$ from the surface of the earth. The motion of the ball is affected by a drag force equal to $m\gamma v^2$ (where, m is mass of the ball, v is its instantaneous velocity and $\gamma$ is constant). Time taken by the ball to rise to its maximum height is

A 10 kg block is kept on a horizontal surface and Ram is trying to pull it with a force of 5 N. Given coefficient of static friction is 0.2 and coefficient of Kinetic friction ${\mu }_K$ = 0.1 Which of these statements is/are correct.

Two half lenses $L_1({\mu }_1=1.4)$ & $L_2({\mu }_2=1.5)$ having radius of the curvature $R=20\text{cm}$ are placed together as shown. Find the position of the image of the parallel beam of light with respect to the common principal axis.

A stream of electrons from a heated filament was passed between two charged plates kept at a potential difference V esu. If e and m are charge and mass of an electron respectively, then the value of $h/\lambda$ (where $\lambda$ is wavelength associated with electron wave) is given by:

When a conductance cell was filled with $0.0025M$ solution of $K_{2}S{O}_4$, its resistance was $326ohm$. What will be the specific resistance of $K_{2}S{O}_4$?



Given:

$\text{Length of cell}=100cm$

$\text{Cross-sectional area}=2.14\times {10}^{-4}c{m}^2$.

Ball $A$ is dropped from the top of a building. At the same instant, ball $B$ is thrown vertically upwards from the ground. When the balls collide, they are moving in opposite directions and the speed of $A$ is twice the speed of $B$. At what fraction of the height of the building did the collision occur?

A particle starts from origin $\text{O}$ from rest and moves with a uniform acceleration along the positive $x-$axis. Identify all figures that correctly represent the motion quantitatively.

($a=$ acceleration, $v=$ velocity, $x=$ displacement, $t=$ time)

Case study $\left(1\right)$



A car battery with a $12\text{V}$ of emf and an internal resistance of $0.04\Omega$ is being charged with a current of $50\text{A}.$



$\left(ii\right)$The rate at which energy is being dissipated as heat inside the battery is

The half-life of a radioactive isotope $\text{X}$ is $20\text{years}.$ It decays into another element $\text{Y}$, which is stable. The two elements $\text{X}$ and $\text{Y}$ were found to be in the ratio $1:7$, in a sample of a given rock. The age of the rock is estimated to be,

If the period of revolution of an artificial satellite just above the earth's surface is T and the density of earth is $\rho$, then $\rho T^2$ is

The molecular weight of hydrogen molecules is $M=2.408\times {10}^{-3}\text{kg/mol}.$ Calculate the root mean square speed of hydrogen molecules $\left(H_2\right)\text{at}300\text{K}.$

A body cools down from ${40}^{\circ }\text{C}$ to ${35}^{\circ }\text{C}$ in $10$ minutes and to ${30}^{\circ }\text{C}$ in another $15$ minutes. Find the temperature of the surroundings.

A block of mass 250 g is kept on a vertical spring of spring constant 100 N/m fixed from below. The spring is now compressed to have a length 10 cm shorter than its natural length and the system is released from this position. How high does the block rise from this position? Take g = 10 m/$s^2$.

A body of weight 2 kg is suspended as shown in the figure. The tension $T_1$ in the horizontal string (in kg wt) is

If frequency of $k_{\alpha }$ x - ray emitted from the element with atomic number $31$ is $f$, then frequency of $k_{\alpha }$ x - ray emitted from the element with atomic number $51$ would be (Assuming screening constant for $k_{\alpha }$ x - ray is $1$)

Find the magnitude of electric field due to a dipole at a point $\text{P}$ along the line joining point $\text{P}$ and centre of dipole as shown in figure.

In a cathode ray tube electric and magnetic fields are simultaneously applied mutually at right angles to each other and also at right angles to the direction of motion of the cathode rays, such that the cathode ray beam is un-deflected. If the electric intensity is 500 $Vc{m}^{-1}$ and the magnetic induction is 0.01 tesla, the velocity of the cathode ray particles is

Figure shows two capacitors connected with a battery in a circuit.





On moving from left to right on the branch containing the capacitors, the correct graph representing potential $\left(V\right)$ vs distance $\left(x\right)$ will be:

$(C_1=3\mu \text{F};C_2=1\mu \text{F})$

Which of the following velocity time graphs shows a realistic situation for a body in motion?

A stationary object is released from a point $\text{P}$ at a distance $3R$ from the center of the moon which has radius $R$ and mass $M$. Which of the following are the correct expression for speed of the object on hitting the moon?

An object of mass $50\text{kg}$ is raised to a height of $10\text{m}$ above the ground. If the object is allowed to free fall. What is kinetic energy, when it is half way down? ($g=10{\text{m/s}}^2$)

A square section of side $20\text{cm}$ is removed from the bigger square of side $40\text{cm}$ as shown in the figure. Find the center of mass of the remaining portion of the square.