Explore topic-wise InterviewSolutions in Current Affairs.

Find the average velocity of a projectile between the instants it first crosses half the maximum height and then again does the same. It is projected with a speed $u$ at an angle $\theta$ with the horizontal. (no need to calculate, just work it out mentally!).

Two concentric spheres of radii $r_1$ and $r_2$ carry charges $q_1$ and $q_2$ respectively. If the surface charge density $\left(\sigma \right)$ is the same for both the spheres, the electric potential at the common centre will be

The electron in the ground state of the hydrogen atom absorbs 12.1 eV of energy. It will jump to the orbit

A uniform cylindrical wire is subjected to a longitudinal tensile stress of $5\times {10}^{7}N/m^2$. Young’s modulus of the material of the wire is $2\times {10}^{11}N/m^2$. The volume change in the wire is $0.02\%$. The magnitude of fractional change in the radius is

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 second hand of a clock is 2.0 cm long .calculate the speed of the tip of the hand, the velocity at 0 seconds and at 15 seconds, the change in velocity from 0.0 to 15 seconds, and average acceleration.

An ideal solenoid of cross-sectional area ${10}^{-4}{m}^2$ has 500 turns per metre. At the centre of this solenoid, another coil of 100 turns is wrapped closely around it. If the current in the coil changes from 0 to 2 A in 3.14 millisecond, the emf developed in the second coil is

The poles of a horse-shoe magnet each of pole strength $2\text{Am}$ are at $4\text{cm}$ apart.



$\left(ii\right)$The magnetic induction at the mid point between the poles is $\text{(in}\text{T})$

A charge ${10}^{-9}\text{C}$ is located at the origin of a coordinate system and another charge $Q$ at $(2,0,0)$. If the $x-$ component of the electric field at $(3,1,1)$ is zero, calculate the value of $Q$.

A ball crosses point p with speed 6 $m/s$ and returns same point p with speed 8 $m/s$ in 5 seconds. Assuming acceleration($a$) is uniform, find the magnitude of $a$

A body of mass $m_1$ elastically collide with another stationary body of mass $m_2$
$\begin{array}{cc}\text{Column - I}& \text{Column -II}\\ \text{(a) After the collision, velocity of second}& \left(p\right)>1\\ \text{body is maximum when}\frac{m_1}{m_2}\text{is}& \\ \text{(b) After the collision, the momentum}& \left(q\right)<1\\ \text{of second body is maximum when}\frac{m_1}{m_2}\text{is}& \\ \text{(c) After the collision, K.E. of second}& \left(r\right)=1\\ \text{body is maximum when}\frac{m_1}{m_2}\text{is}& \\ \text{(D) For elastic collision, coefficient of}& \left(s\right)=0\\ \text{restitution is}& \end{array}$

A fan at a rock concert is 30 m from the stage, and at this point the sound intensity level is 110 dB.How much energy is transferred to her eardrums each second? (Assume eardrum to be circular with a radius of 10mm)

A particle moving at speed $u$ on a circular path of radius $R$ begins to speed up at a constant rate. The magnitude of change in its velocity vector is $2u$, when it completes one fourth revolution. The magnitude of its radial acceleration after completing one-fourth revolution will be

A perfectly reflecting body (sphere in shape) is placed on a path of parallel light beam of intensity $I$ shown in figure. One end of a spring is attached to the centre of the sphere and the other end to a rigid wall as shown in the figure. Sphere is in equilibrium. Spring constant of spring is $K$. Then compression in spring is

(Radius of sphere is $R$, $c$ is the velocity of light and neglect any thermal effect and friction )

A block B is pushed momentarily along a horizontal surface with an initial velocity V, if $\mu$ is the coefficient of sliding friction between B and the surface, the velocity of block B becomes half after time

If two bodies are in equilibrium in one frame,will they be equilibrium in all frame?

Two charged metallic spheres of radii 2r and 3r are brought into contact and then separated at large distance. Ratio of their respective charges is

For a transition curve, the polar deflection angle ${\alpha }_s$ and the spiral angle ${\Delta }_s$ are related to each other by the expression:

For the reaction $H_{2}O\left(s\right)\leftrightharpoons H_{2}O\left(l\right)$ at 0°C and normal pressure

Statements:

All hot are seats.

All belts are seats.

Conclusions

I. All hot are belts.

II. All belt are hot.

Each capacitor in the figure has a capacitance of $10\mu \text{F}$. The emf of the battery is $100\text{V}$. Find the ratio of the energy stored in $b$ to $a$.

A point moving with constant acceleration from $A$ to $B$ in the straight line $AB$ has velocities $u$ and $v$ at $A$ and $B$ respectively. Find its velocity at $C$, the mid point of $AB$.

1. 1.8

Light is reflected normally from thin layer of oil over water. Refractive index of oil is 1.2 and that of water is $\frac{4}{3}$. Layer of oil looks shining orange colour $(\lambda =600nm)$ if thickness of oil layer is

A cube of side $a$ has point charges, $+Q$ located at each of its vertices, except at the origin, where the charge is $–Q$. The electric field at the centre of the cube is :