Explore topic-wise InterviewSolutions in Current Affairs.

A $700\text{g}$ solid cube having an edge of length $10\text{cm}$ floats in water. How much volume of the cube is outside the water? Density of water $=1{\text{g/cm}}^3.$

A stone is thrown vertically upwards from top of a tower of 85m high, reaches the ground in 5s. Find

1. The greatest height above the ground.

2. The velocity with which it reaches the ground.

3. The time taken to reach the maximum height.

(g=10m/s)

Two persons A and B having masses $55\text{kg}$ & $65\text{kg}$ respectively, are sitting at the opposite ends of a stationary boat. The length of the boat is $3\text{m}$ and the weight is $100\text{kg}$. Person A walks upto person B & sits with him. If the boat is in still water, the centre of mass of the system shifts by

In a circus an artist is swinging on a trapeze. What kind of motion is it?

In a conducting hollow sphere of inner and outer radii $5\text{cm}$ and $10\text{cm}$, respectively, a point charge $1\text{C}$ is placed at point $A$, that is $3\text{cm}$ from the center $C$ of the hollow sphere. An external uniform electric field of magnitude $20\text{N/C}$ is also applied. Net electric force on this charge is $15\text{N}$, away from the center of the sphere as shown in the figure. Find the magnitude of net force exerted on the charge placed at point $A$ by the induced charges on the sphere.

p – V diagram of the ideal gas is as shown in figure. Work done by the gas in the process ABCD is

The wavelength of the $K_{\alpha }$ line for an element of atomic number $57$ is $\lambda$. The wavelength of the $K_{\alpha }$ line for the element of atomic number 29 is

A bob of mass m is suspended by a massless string of length L. The horizontal velocity v at position A is just sufficient to make it reach the point B. The angle $\theta$ at which the speed of the bob is half of that at A satisfies

An incompressible liquid flows through a horizontal tube as shown in the figure. Then the velocity $v$ of the liquid coming out of the tube of area $1.5A$ is:

A spherical convex surface of radius of curvature $10\text{cm}$ has object and image in mediums of refractive index $1.0$ and $\frac{4}{3}$ respectively. Its power will be

A silver atom in a solid oscillates in simple harmonic motion in some direction with a frequency of ${10}^{12}/sec.$ What is the force constant of the bonds connecting one atom with the other ? (Molecular wt. of silver $=108g$ and Avagadro number $=6.02\times {10}^{23}gm$ mole ${}^{-1}$ )

Two thin rod of mass $m$ and length $l$ are joined together to make a ${}^{\prime }{L}^{\prime }$ shaped structure. Find out moment of inertia of structure about an axis passing through their common joining point and perpendicular to the plane of structure.

An electron is constrained to move along the $y-$axis with a speed of $0.1c$ ($c$ is the speed of light) in the presence of electromagnetic wave, whose electric field is $\overrightarrow{E}=30\hat{j}\sin (1.5\times {10}^{7}t-5\times {10}^{-2}x)\text{V/m}$. The maximum magnetic force experienced by the electron will be



(given $c=3\times {10}^8{\text{ms}}^{-1}$ & electron charge $=1.6\times {10}^{-19}\text{C})$

Two long parallel wires seperated by 20 cm and carries currents in same direction, $i_1=2A$ & $i_2=4A$, find the force acting per unit length between wires ?

A circular road of radius 50 m has the angle of banking equal to 30^{\circ}. At what speed should a vehicle go on this road so that the friction is not used ?

Figure 7.21 shows a
series LCR circuit connected to a variable frequency 230 V
source. L = 5.0 H, C = 80μF,
R = 40 Ω

(a) Determine
the source frequency which drives the circuit in resonance.

(b) Obtain the impedance of the circuit and the amplitude of
current at the resonating frequency.

(c) Determine the rms potential drops across the three
elements of the circuit. Show that the potential drop across the LC
combination is zero at the resonating frequency.

A plane electromagnetic wave travels in vacuum along z-direction. What can you say about the directions of its electric and magnetic field vectors? If the frequency of the wave is 30 MHz, what is its wavelength?

Two long parallel straight wires, each carrying a current I are separated by a distance r. If the currents are in opposite directions, then the strength of the magnetic field at any point midway between the two wires is

A fundamental particle of mass $m$ and charge $+e$ is projected, towards a heavy particle of charge $Ze$ (when $Z>0$) with velocity $v$, distance of nearest approach is:-

A man of mass M is standing on a plank kept in a box. The plank and box as a whole has mass m. A light string passing over a fixed smooth pulley connects the man and box. If the box remains stationary, find the tension in the string and the force exerted by the man on the plank.

A magnet is made to oscillate with a particular frequency, passing through a coil as shown in figure. The time variation of the magnitude of EMF generated across the coil during one cycle is:

Let $V_G$ and $E_G$ denote the gravitational potential and field respectively in a region, then choose the wrong statement.

A body of mass $1kg$ is traveling with a velocity of $3m/s$ accelerates uniformly to acquire a velocity of $8m/s$ in $2s$. Find the force acting on the body.

For photo-electric effect with incident photon wavelength $\lambda$, the stopping potential is $V_0$. Identify the correct variation(s) of $V_0$ with $\lambda$ and $1/\lambda$.

A tunnel is dug along a diameter of the earth. Find the force on a particle of mass m placed in the tunnel at a distance x from the centre.

A solenoid of $2\text{m}$ long has $200$ turns per meter and current $2\text{A}$ flows through it as shown below. What would be the magnetic field at the point $\text{P}$ on the axis of the solenoid $5\text{m}$ away from the centre ?

A body travels 3 km towards east , 4km towards north and finally 9 km towards east. Find the resultant displacement.

Two blocks of masses $m_1$ and $m_2$ are joined by a wire of Young’s modulus Y via a massless pulley. The area of cross-section of the wire is S and its length is L. When the system is released, increase in length of the wire is

A thin uniform rod with negligible mass and length $0.2\text{m}$ is attached to the floor by a frictionless ring at point $\text{P}$. A horizontal spring with spring constant $k=4.80{\text{Nm}}^{-1}$ connected to rod, the other end of the spring is fixed with a vertical wall as shown in the figure below. The rod is in a uniform magnetic field $B=0.340\text{T}$ directed into the plane of figure. There is a current $I=6.50\text{A}$ in the rod in the direction shown. Find the energy stored in the spring when the rod is in equilibrium:

Four plates of equal area A are separated by equal distances $d$ and are arranged as shown in the figure. The equivalent capacity is

A man at rest observes that rain is falling vertically downwards. When he moves with a velocity of $3\text{km/h}$, he holds an umbrella at an angle of ${37}^{\circ }$ from the vertical to avoid rain. The velocity of the rain with respect to man is

Two bodies of mass 3 kg and 4 kg are suspended at the ends of massless string passing over a frictionless pulley. The acceleration of the system is $(g=9.8m/s^2)$

A sphere with centre $O$ sits atop a pole as shown in the figure. An observer on the ground is at a distance $50m$ from the foot of the pole. She notes that the angles of elevation from the observer to points $P$ and $Q$ on the sphere are ${30}^{\circ }$ and ${60}^{\circ }$, respectively. Then, the radius of the sphere in meters is

A particle is launched from a horizontal plane with speed $u$ and angle of projection $\theta$. The angular velocity of the particle as observed from point of projection at the time of landing will be:

The position vectors of the vertices $A,B$ and $C$ of a tetrahedron $ABCD$ are $\hat{i}+\hat{j}+\hat{k},$ $\hat{i}$ and $3\hat{i}$ respectively. The altitude from vertex $D$ to the opposite face $ABC$ meets the median line through $A$ of the triangle $ABC$ at a point $E.$ If the length of the side $AD$ is $4$ and the volume of the tetrahedron is $\frac{2\sqrt{2}}{3}$ cubic units, then the position vector(s) of the point $E$ for all its positions is (are)

SI unit of charge is:

A disc of radius $R$ and mass $M$ is pivoted at the rim and is set for small oscillations. If simple pendulum has to have the same period as that of the disc, the length of the simple pendulum should be

A body of mass 'm' moving with a speed 'v' suffers an inelastic collision with another body of 'M' at rest and sticks to it, the ratio of the final kinetic energy of the system to the initial kinetic energy is