Explore topic-wise InterviewSolutions in Current Affairs.

A girl is carrying a school bag $3kg$ on her back and moves $200m$ on a leveled road. The work done against the gravitational force will be $(g=10m{s}^{-2})$

A cannon ball is fired at a speed of $50m{s}^{-1}$, where the angle of projection is ${30}^{\circ }$. Find the maximum height and also the time of flight of the cannon ball. (Take acceleration due to gravity, $g=10m{s}^{-2}$).

Solar radiation emitted by sun resembles to that emitted by a black body at a temperature of $6000\text{K}$. Maximum intensity is emitted at a wavelength of about $4800\AA$. If the sun is cooled down from $6000\text{K}$ to $3000\text{K}$, then the peak intensity would occur at a wavelength of

A stone is dropped from top of a tower. Choose the correct distance-time graph for the motion of stone.



एक पत्थर को एक मीनार के शीर्ष से गिराया जाता है। पत्थर की गति के लिए सही दूरी-समय आरेख का चयन कीजिए।

A student measures the time period of $100$ oscillations of a simple pendulum four times. The data set is $90s,91s,95s$ and $92s$. If the minimum division in the measuring clock is $1s$, then the reported mean time should be

A capacitor, with air in between the plates, is charged to a potential $V_0$, now the battery is removed and a di-electric medium with di-electric constant $k$ is filled in the space between the plates, due to this the potential difference is dropped to $\frac{V_0}{10}$. Find the value of $k?$

A spherical conducting shell of inner radius $r_1$ and outer radius $r_2$ has a charge Q. (a) A charge q is placed at the centre of the shell. What is the surface charge density on the inner and outer surfaces of the shell? (b) Is the electric field inside a cavity (with no charge) zero, even if the shell is not spherical, but has any irregular shape? Explain.

If an object made of substance A is rubbed with an object made of substance B, then A becomes positively charged and B becomes negatively charged. If, however, an object made of substance A is rubbed against an object made of substance C, then A become negatively charged. What will happen if an object made of substance B is rubbed against an object made of substance C?

The pulley system (shown in the figure) is placed on a smooth horizontal surface which is rotating at an angular velocity of $\text{1 rad/s}$ in a circle of radius $\text{10 m}$ (in a horizontal plane). The pulley is fastened to the table. Two blocks of masses $m_1$= $\text{3 kg}$ and $m_3=\text{10 kg}$ are placed on the table. A third block (rough) of mass $m_2=\text{2 kg}$ is placed over $m_1$ Find the minimum frictional force between the blocks $m_1$ and $m_2$ such that they move together. Assume the lengths of the strings to be very small when compared to the radius of the circle of rotation.

In an experiment on photoelectric effect, the emitter and the collector plates are placed at a separation of $10\text{cm}$ and are connected through an ammeter without any cell. A magnetic field $B$ exists parallel to the plates. The work function of the emitter is $2.39\text{eV}$ and the light incident on it has wavelengths between $400\text{nm}$ and $600\text{nm}$. Find the minimum value of $B$ for which the current registered by the ammeter is zero. Neglect any effect of space charge.

A ray of light undergoes deviation of ${30}^{\circ }$ when incident on an equilateral prism of refractive index $\sqrt{2}$. The angle made by the ray inside the prism with the base of the prism is

A wave pulse is described by $y(x,t)=\left[4e^{-(2x-10t{)}^2}\right]\text{m}$. The speed of this wave pulse is -

A Carnot engine absorbs $Q_1$ amount of heat from a reservoir at an absolute temperature $T$ and rejects heat to a sink at a temperature of $T/3$. The amount of heat rejected is

A dip needle vibrates in the vertical plane perpendicular to the magnetic meridian. The time period of vibration is found to be 2 seconds. The same needle is then allowed to vibrate in the horizontal plane and the time period is again found to be 2 seconds. Then the angle of dip is

If ${\mu }_s\text{and}{\mu }_k$ represent the coefficients of static and kinetic friction with appropriate suffixes for the two bodies shown, find the acceleration of the system. Take $g=10m/s^2$.

Total internal reflection occurs when

A particle of mass $50\text{gm}$ is tied to a string of length $30\text{cm}$ is performing circular motion in a vertical plane. What will be the angular speed of particle, if tension in the string becomes zero at the top most position of circular path. (Take $g=10{\text{m/s}}^2$).

An uncharged capacitor of $50\mu \text{F}$ is connected to a battery of $10\text{V}$. What amount of energy supplied by the battery is lost as heat while charging the capacitor ?

The plot of velocity versus time graph for a particle moving along a straight line is shown.



The value of dot product of velocity and acceleration of particle at $t=2s$ is

1. 0

A scooter starting from rest moves with a constant acceleration for a time $\Delta$ $t_1$, then with a constant velocity for the next $\Delta$ $t_2$, and finally with a constant deceleration. A person of mass 50 kg on the scooter, behind the driver manages to stay at rest with respect to the scooter without touching any other part. The force exerted by the seat on the man is

Take g=10m/ $s^2$

Two identical P-N junctions may be connected in
series with a battery in three ways. The potential drops across the two P-N junctions
are equal in

The kinetic energy of an electron is $5\text{eV}$. Calculate the de-Broglie wavelength associated with it. $(h=6.6\times {10}^{-34}\text{Js},m_e=9.1\times {10}^{-31}\text{kg})$

A number of capacitors, each of equal capacitance $C$, are arranged as shown in the figure. The equivalent capacitance between A and B is

In a coil of resistance of $10\Omega$, the induced current $i$ developed by changing magnetic flux through it, is shown in the figure as a function of time. The magnitude of changing flux through the coil in $\text{Wb}$ is

A rocket with a lift-off mass $3.5\times {10}^{4}kg$ is blasted upwards with an initial acceleration of $10m/s^2$. Then the initial thrust of the blast is

Topic pure rolling on inclined plane

For the condition for no slipping why should the force of friction be less than the limiting friction??

Find a
unit vector perpendicular to each of the vector
and,
where
and.

The energy of a $100\mu \text{F}$ capacitor charged to $6\text{kV}$ is used to lift a $50\text{kg}$ mass (by powering a motor by energy of capacitor) without incurring any losses. What would be the greatest vertical height through which mass could be raised?

(Take $g=10{\text{m/s}}^2$)