Explore topic-wise InterviewSolutions in .

Twelve capacitors each of capacitance $C$ are connected together so that each lies along the edge of the cube as shown in figure. The equivalent capacitance between $1$ and $4$ will be:

An electric bulb of volume $250{\text{cm}}^3$ was sealed off during manufacture at a pressure of ${10}^{-3}\text{mm}$ of mercury at ${27}^{\circ }C$. Compute the number of air molecules contained in the bulb. Given that $R=8.31\text{J/mole-K}$ and $N_A=6.02\times {10}^{23}$ per mole

(correct answer + 2, wrong answer - 0.50)

A lens forms a virtual, erect and diminished image of an object placed at a distance of $2m$ from it. The size of the image formed is half of that of the object. Which of the following statement is correct regarding the nature and focal length of the lens?

The figure shows two short bar magnets of equal length $l$ having magnetic moments ${\overrightarrow{M}}_1$ and ${\overrightarrow{M}}_2$ respectively, with their centres of separation being $r$. If $l<<r$, what would be the magnitude of force on the magnet $2$ by $1$ ?

Intensity of sunlight is observed as $0.092{\text{Wm}}^{-2}$ at a point in free space. What will be the peak value of magnetic field at that point ?

$({\epsilon }_0=8.85\times {10}^{-12}{\text{C}}^2{\text{N}}^{-1}{\text{m}}^{-2})$

Train $A$ travelling at $60\text{km/h}$ overtakes another train $B$ travelling at $42\text{km/h}$. Assuming each train to be $50\text{m}$ long and initially train $A$ to be just behind the train $B$, the total road distance used for the overtake is closest to

A convex mirror:

A point source of light of power ‘P’ and wavelength '$\lambda$' is emitting light in all directions. The number of photons present in a spherical region of radius ‘r’ to radius ‘2r’ with centre at source, is

By what distance do the wedges move, if the horizontal plank moves by $x\text{cm}$ downwards?

If the $Si$ diode and the $Ge$ diode start conducting at $0.7\text{V}$ and $0.3\text{V}$ respectively, in the given circuit then the current flow through the resistance in the given circuit is

In a YDSE both slits produce equal intensities on the screen. A $100\%$ transparent thin film is placed in front of one of the slits. Now the intensity of the geometrical centre of system on the screen becomes $75\%$ of the previous intensity. The wavelength of the light is $6000\stackrel{\circ }{A}$ and ${\mu }_{glass}=1.5$. The thickness of the film cannot be:

A mirror of radius of curvature $20\text{cm}$ and an object which is placed at a distance of $15\text{cm}$ are both moving with the velocities $1\text{m/s}$ and $10\text{m/s}$ as shown in the figure. The velocity of the image is

In a radioactive material, the fraction of an active material remaining after time $t$ is $\frac{9}{16}$. The fraction that was remaining after $\frac{t}{2}$ is-

A particle moves along a circle with a constant angular speed $\omega$ . Its displacement, with respect to the position of the particle at time t =0 is plotted against time. The graph would look like:

A man $A$ at radius $2\text{m}$ and other man $B$ at radius $3\text{m}$ perform uniform circular motion on the floor of a merry-go-round as the ride turns. They are on the same radial line. At one instant, the acceleration of the man $A$ is $(2\hat{i}+4\hat{j}){\text{m/s}}^2$. At that instant and in unit-vector notation, what is the acceleration of man $B$?

A resistance of $4\Omega$ and a wire of length $5\text{m}$ and resistance $5\Omega$ are joined in series and connected to a cell of EMF $10\text{V}$ and internal resistance $1\Omega$. A parallel combination of two identical cells is balanced across $300\text{cm}$ length of the wire. The EMF $E$ of each cell is -

1. 173.1

1. 298

If $C$ is the critical angle and $n$ is the refractive index of a denser medium with respect to the rarer medium, $sinC\times n$ is .

Initially a circuit consist of five identical conductors but now two similar conductors are added as shown by the dashed line in figure. Find the ratio of final resitance to initial resistance between the point $A$ and $B$.

Two identical glass rods $S_1$ and $S_2$ (refractive index = 1.5) have one convex end of radius of curvature $10cm$. They are placed with the curved surfaces at a distance d as shown in the figure, with their axes (shown by the dashed line) aligned. When a point source of light $P$ is placed inside rod $S_1$ on its axis at a distance of $50cm$ from the curved face, the light rays emanating from it are found to be parallel to the axis inside $S_2$. The distance $d$ is

A charged particle of mass $m$ and charge $q$ travels in a circular trajectory of radius $r$ in a magnetic field $B.$ The time taken by the particle to complete one revolution is

A dumb-bell consists of two identical small balls of mass $\frac{1}{2}$ kg each connected to the two ends of a 50 cm long light rod. The dumb-bell is rotating about a fixed axis through the centre of the rod and perpendicular to it at an angular speed of 10 rad/s. An impulsive force of average magnitude 5.0 N acts on one of the masses in the direction of its velocity for 0.10 s. Find the new angular velocity of the system.

Two masses $4\text{g}$ and $12\text{g}$, are placed horizontally at a distance of $12\text{cm}$ from each other. Another mass of $0.5\text{g}$ is placed in between them such that there is no net force acting on it. Find the distance (in $\text{cm}$) of the third mass from the mass of $4\text{g}$.

You have a test tube of length 14 cm. You blow in it and form standing waves. Can you tell the fundamental frequency of standing wave formed in the tube if it was half filled with ice. (i) for diagram 1 (ii) for diagram 2

Given v = 336 $\frac{m}{s}$

Two masses, 'n*m' and 'm', start simultaneously from the intersection of two straight lines with velocities 'v' and 'n*v' respectively. It is observed that the path of their centre of mass is a straight line bisecting the angle between the given straight lines. Find the magnitude of the velocity of centre of mass.[Here $\theta$ = angle between the lines]

The hero of a stunt film fires $50\text{gm}$ bullets from a machine gun, each at a speed of $1.0\text{km/s}$. If he fires $20$ bullets in $4\text{s}$, what average force does he exert against the machine gun during this period?

As the intensity of incident light increases

Add the following vectors:

$\overrightarrow{A}=5\hat{i}+6\hat{j}-10\hat{k}$

$\overrightarrow{B}=-10\hat{i}-6\hat{j}+10\hat{k}$

The
bob A of a pendulum released from 30°
to the vertical hits another bob B
of the same mass at rest on a table as shown in Fig. 6.15. How high
does the bob A rise after the collision? Neglect the size of the bobs
and assume the collision to be elastic.