Explore topic-wise InterviewSolutions in Current Affairs.

A $2\text{kg}$ object is subjected to three forces that give it an acceleration $\overrightarrow{a}=-\left(8\hat{i}\right){\text{m/s}}^2$. If two of the three forces are ${\overrightarrow{F}}_1=(30\hat{i}+16\hat{j})\text{N}$ and ${\overrightarrow{F}}_2=(-12\hat{i}+8\hat{j})\text{N}$, find the third force ($\text{in N}$).

A series combination of $n_1$ capacitors, each of value $C_1$, is charged by a source of potential difference 4V. When another parallel combination of $n_2$ capacitors, each of value $C_2$, is charged by a source of potential difference V, it has the same (total) energy stored in it, as the first combination has. The value of $C_2$, in terms of $C_1$, is then:

In a thin prism of glass (refractive index $1.5$), which of the following relations between the angle of minimum deviations $\left({\delta }_m\right)$ and angle of first refraction of light $\left(r\right)$ through prism will be correct?

A body is projected horizontally from a height of 78.4m with a velocity 10 M/s. Its velocity after 3seconds is ? (G=10m/S2)(take the direction of projection on i vector and vertically upward direction on J vector)

Find $T_1$ in the shown figure. (Assume $g=10{\text{m/s}}^2$)

Two roads one along y-axis and another along a direction at angle $\theta$ with x-axis as shown in figure. Two cars 'A' and car 'B' are moving along the roads. Consider the situation of the diagram. Draw the direction of car 'B' as seen from car 'A'.

In the following circuit, the output $\text{Y}$ for all possible inputs $\text{A}$ and $\text{B}$ is expressed by a truth table:

The planet mercury is revolving in an elliptical orbit around the sun as shown in the figure. The kinetic energy of mercury will be greater at

A conductor initially free from charge is charged by repeated contacts with a plate which after each contact is replenished to a charge $Q$. If $q$ is the charge on the conductor after first operation, then the maximum charge which can be given to the conductor in this way will be:

(When 2 conductors are in contact, potential on them becomes equal)

If $(x,y,z)$ be an arbitrary point lying on a plane $P$ which passes through the points $(42,0,0),$ $(0,42,0)$ and $(0,0,42),$ then the value of the expression $3+\frac{x-11}{(y-19{)}^2(z-12{)}^2}+\frac{y-19}{(x-11{)}^2(z-12{)}^2}+\frac{z-12}{(x-11{)}^2(y-19{)}^2}-\frac{x+y+z}{14(x-11)(y-19)(z-12)}$ is equal to :

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A hollow cylindrical tube of a metal with inner and outer radii as $r_1$ and $r_2$ respectively carries a current $I$. The magnetic field inside the tube at a distance $r$ (shown in the diagram) from the centre will be

The rest mass of the photon is

If $P_1$ represents momentum of a matter particle and $P_2$ is momentum of a photon, the ratio of $P_1:P_2$ is, ($\lambda$ is the wavelength of the photon)

Here, $v$ is the velocity of the particle.

A source moves towards a stationary observer with speed $40\text{m/s}$. The source sounds a whistle and its frequency registered by the observer is $n_1$. If the source's speed is reduced to $20\text{m/s}$, the frequency registered is $n_2$. If the speed of sound is $340\text{m/s}$, then the ratio $\frac{f_1}{f_2}$is



[Assume, medium is stationary]

A $750\text{Hz},20\text{V}$ source is connected to a resistance of $100\Omega ,$ an inductance of $0.1803\text{H}$ and a capacitance of $10\mu \text{F}$, all are in series. The time in which the resistance will get heated by ${10}^{\circ }\text{C}$ is-



[ $\text{Use, thermal capacity}=2\text{J}{/}^{\circ }\text{C}$]

If the coefficient of friction between $A$ and $B$ is $\mu$, the maximum acceleration of the wedge $A$ for which $B$ remains at rest with respect to the wedge is

An ideal monatomic gas at $300\text{K}$ expands adiabatically to $8$ times its volume. What is the final temperature?

In a vibration magnetometer, the time period of a bar magnet oscillating in horizontal component of earth's magnetic field is 2 sec. When a magnet is brought near and parallel to it, the time period reduces to 1 sec. The ratio H/F of the horizontal component H and the field F due to magnet will be [MP PMT 1990; Pb PET 2000]

A particle moving along positive $x-$axis with a speed $5{\text{ms}}^{–1}$ suddenly changes its direction along the positive $y-$axis with the same speed. The change in velocity $\Delta \overrightarrow{v}$ of the particle is -

The linear charge density of a thin rod of length $l$ varies with the distance $x$ from the left-most end as $\lambda ={\lambda }_0{x}^2(0\le x\le l)$. The total charge on the rod is

At t = 0, a transverse wave pulse in a wire is described by the function, $y=\frac{6}{x^2+3}$ where x and y are in metres. Write the function y (x, t) that describes this wave if it is travelling in the positive x-direction with a speed of 4.5 m/s.

Calculate the electric field in a copper wire of cross-sectional are 2.0 $m{m}^2$ carrying a current of 1 A. The resistivity of copper = 1.7 $\times {10}^{-8}\Omega m.$

Consider the situation shown in the figure. The wires $P_1{Q}_1$ and $P_2{Q}_2$ are made to slide on the rails with the same speed $5{\text{cm s}}^{-1}$ and have equal resistance of $2\Omega$. Find the electric current in the $19\Omega$ resistor if both the wires move towards right.

A cube of wood supporting a $200\text{g}$ mass just floats in water. When the mass is removed, the cube rises by $2\text{cm}$. What is the size of the cube?

Density of water = $1{\text{g/cm}}^3$.

Assume initial and final situations to be under equilibrium.

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An e.m.f. of $15\text{V}$ is applied in a circuit containing $5\text{H}$ inductance and $10\Omega$ resistance. The ratio of the currents in the circuit at time $t=1\text{s}$ and $t=\infty$ is

A body crosses the topmost point of a vertical circle at critical speed. What will be its centripetal acceleration (in ${\text{m/s}}^2$) when the string becomes horizontal?

A bomb of mass $3\text{m}$ is kept inside a closed box of mass $3\text{m}$ and length $4\text{L}$ at its centre. It explodes in two parts of mass $m$ and $2m$. The two parts move in opposite direction and stick to the opposite side of the walls of box. Box is kept on a smooth horizontal surface.
What is the distance moved by the box during this time interval?

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