Explore topic-wise InterviewSolutions in Current Affairs.

Find the acceleration of block of mass $m$ along the inclined plane $\left(a_x\right)$ if the acceleration of wedge, $b=4{\text{m/s}}^2$. All accelerations are w.r.t. to the ground and assume that the surface and pulley are smooth and the string is inextensible.

What should be the minimum height of the mirror so that a person can see the full wall of height h behind him? (Assume the man to be at the centre of the wall and the mirror.)

A body of mass 5 kg explodes at rest into three fragments with masses in the ratio 1 : 1 : 3. The fragments with equal masses fly in mutually perpendicular directions with speeds of 21 m/s. The velocity of the heaviest fragment will be

If we are said to find pressure at sea level of 3000m,shall we consider the atmospheric pressure also

A glass full of water has a bottom of area 20 $c{m}^2$, top of area 20 cm 2, height 20 cm and volume half a litre. (a) Find the force exerted by the water on the bottom. (b) Considering the equilibrium of the water, find the resultant force exerted by the sides of the glass on the water. Atmospheric pressure =$1.0\times {10}^{5}NM-2$. Density of water = 1000 kg $m^{-3}$ and g = 10 m $s^{-2}$. Take all numbers to be exact.

A sphere of mass M and radius r shown in figure slips on a rough horizontal plane. At some instant it has translational velocity $v_0$ and rotational velocity about the centre $\frac{v_0}{2r}$. Find the translational velocity after the sphere starts pure rolling.

For the given oscillatory motion, $F=-k(x-b{)}^3$, find out the mean position of the particle.

A 10 henry inductor is carrying a current 2A. Rate at which the current be changed so that an e.m.f. of 100V is induced is

In 1 minute, how much energy does a $100W$ electric bulb consumes?

A $500\text{kg}$ car, moving with a velocity of $36{\text{kmh}}^{-1}$ on a straight road unidirectionally, doubles its velocity in one minute. The power delivered by the engine for doubling the velocity is

In the figure shown, find out angular velocity of A with respect to B.

A ball is suspended by a thread of length l at the point O on the wall, forming a small angle $\beta (\beta >\alpha )$ with the vertical (see the figure). Then the thread with the ball was deviated through a small angle $\beta$ and set free. Assuming the collision of the ball against the wall to be perfectly elastic, the period of oscillation of this pendulum is:

A block of mass $M=40\text{kg}$ is released on a smooth incline from the point shown in the figure. After travelling through a length of $30\text{cm}$, it strikes an ideal spring of force constant $k=1000\text{N/m}$. It compresses the spring and then gets pushed back. How much time after its release will the block be back again to the point of release?
[Take $g=10{\text{m/s}}^2$]

The speed $v$ of a particle moving along a straight line, when it is at a distance $x$ from a fixed point on the line, is given by $v^2=144-9x^2$.
Choose the wrong option.

If the m mass of the substance undergoes a change from one state to another, then the amount of heat required for the process is

A truck starts from rest and accelerates uniformly at $2.0m{s}^{-2}$. At t = 10 s, a stone is dropped by a person standing on the top of the truck (6 m high from the ground). What are the (a) velocity, and (b) acceleration of the stone at t = 11 s? (Neglect air resistance.)

In the current circuit diagram when the current reaches steady state in the circuit, the charge on the capacitor of capacitance C will be

In the figure shown below, two metallic slabs of same area of cross section and thickness having thermal conductivities $500{\text{W/m}}^{\circ }\text{C}$ and $600{\text{W/m}}^{\circ }\text{C}$ respectively are connected to the same temperature difference in parallel combination. Find the equivalent thermal conductivity (in ${\text{W/m}}^{\circ }\text{C}$)

A car of 100 HP is moving with a constant velocity of 72 km/hour. The forward force exerted by the engine of the car is

On the cylinder of radius R in the figure, which is rolling with velocity of centre of mass $v=\frac{\omega R}{4}$ towards right ($\omega$ is clockwise), find the velocities (magnitude) at points A, B, C, D.

The given truth table is for

$\begin{array}{cc}Input& Output\\ A\mid B& Y\\ 0\mid 0& 1\\ 0\mid 1& 1\\ 1\mid 0& 1\\ 1\mid 1& 0\end{array}$

Three point masses, each of mass $m$ are placed at the corners of an equilateral triangle of side $l$. The moment of inertia of this system about an axis along one of the sides of the triangle is

In the following diagram, the charge and potential difference across 8 $\mu F$ capacitance will be respectively

An object suspended from a spring exhibits oscillations of period T. Now the spring is cut in two halves and the same object is suspended with two halves as shown in figure. The new time period of oscillation will become:

System is shown in the figure. Velocity of sphere A is 9 m/s. Then speed of sphere B will be

plot a graph showing the variation of current density (j) versus the electric field (E) for two conductors of different materials. What information from this plot regarding the properties of the conducting material, can be obtained which can be used to select suitable materials for use in making (i) standard resistance and (ii) connecting wires in electric circuits?

Electron drift speed is estimated to be of the order of $mm{s}^{-1}$ Yet large current of the order of few amperes can be set up in the wire. Explain briefly.

An alternating voltage $v\left(t\right)=220\sin 100\pi tvolt$ is applied to a purely resistive load of $5\Omega$. The time taken for the current to rise from half of the peak value to the peak value is

A spectrometer gives the following reading when used to measure the angle of a prism.
Main scale reading : 58.5 degree
Vernier scale reading : 09 divisions
Given that 1 division on main scale corresponds to 0.5 degree. Total divisions on the vernier scale is 30 and match with 29 divisions of the main scale. The angle of prism from the above data is

An air column closed at one end and open at the other end resonates with a tuning fork when the length of the column is smallest and equal to $50\text{cm}$. The next larger length of column resonating with same tuning fork is

A block rests on a horizontal table which is executing an SHM in the horizontal plane with an amplitude a. If the coefficient of friction is m, the block just starts to slip when the frequency of oscillation is:

The power factor of the circuit is $\frac{1}{\sqrt{2}}$. The capacitance of the circuit is equal to

The energy stored in the system of capacitors shown in the circuit is (Capacitance of each capacitor is $C=0.1\mu F)$

In a container two gases He and $O_2$ are mixed with 1 mole of each gas. The average value of $\frac{CP}{Cv}$ for the mixture will be

A block of mass m attached to an ideal spring of spring constant K is placed on a smooth horizontal surface between two fixed elastic walls AB and CD as shown. The block is at a distance d from CD and spring is in its natural position. The maximum velocity with which the block can be projected towards CD so that block performs complete SHM.

In an a.c. circuit, the instantaneous values of e.m.f. and current are $E=200sin314t\left(volt\right)andI=sin(314t+\frac{\pi }{3})A$. The average power consumed in watts is

An e.m.f. of 20 volt is applied in a circuit containing 5 henry inductance and 10 ohm resistance. The ratio of the currents at time $t=\infty$ and at t = 1 second is

A wheel has six equally spaced thin spokes of length $20\text{cm}$. It is rotating about an axis $\text{xx'}$ which is perpendicular to its plane and passing through its center with $5\text{rev/sec}$. What should be the minimum velocity of an arrow of length $30\text{cm}$ to pass the wheel without hitting any spoke. (Arrow is projected parallel to the axis).

One mole of an ideal monatomic gas has initial temperature $T_0$, is made to go through the cycle $abca$ as shown in fig. If $U$ denotes the internal energy, then choose the correct alternative.

The flow speeds of air on the lower and upper surfaces of the wing of an aeroplane are $v$ and $\sqrt{2}v$ respectively. The density of air is $\rho$ and surface area of wing is $A$. The dynamic lift on the wing is:

A water cooler of storage capacity $120\text{litres}$ can cool water at a constant rate of $P$. In a closed circulation system (as shown schematically in this figure), the water from the cooler is used to cool an external device that constantly generates $3\text{kW}$ of power (thermal load). The temperature of the water fed into the device cannot exceed ${30}^{\circ }\text{C}$ and the entire $120\text{litres}$ of water is initially cooled to ${10}^{\circ }\text{C}$. The entire system is thermally insulated. The minimum value of $P$ for which the device can be operated for 3 hours (taking the specific heat capacity of water $=4.2{\text{kJ kg}}^{-1}{\text{K}}^{-1}$ and the density of water $=1000{\text{kg m}}^{-3})$ is

A capillary tube $A$ is dipped in water. Another identical capillary tube $B$ is dipped in soap- water solution. Which of the following shows the relative nature of the liquid columns in the two tubes? Consider the surface tension of soap solution and water to be $0.073\text{N/m}$ and $0.025\text{N/m}$ respectively at room temperature.

Find the amplitude of the electric field in a parallel beam of light of intensity $2.0W{m}^{-2}$

A string is passing through a ring of mass $m$ as shown. The ring rotates in a horizontal plane of radius $r$ with a constant angular velocity. What should be the maximum speed of rotation so that the string does not get distorted?

A rocket of mass $120\text{kg}$ has $280\text{kg}$ fuel. The relative exhaust velocity of the fuel is $1.8\text{km/s}$ and the rate of consumption of the fuel is $2\text{kg/s}$. Calculate the ultimate vertical speed gained by the rocket. (Take $g=9.8{\text{m/s}}^2$)