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The antenna current of an AM transmitter is 8$A$ when only carrier is sent. It is increased to 8.96$A$ when the carrier is sinusoidally modulated. The percentage modulation is :

Abpoint charge q is placed at the center of a cube of edge a .what is the electric flux through each of the cube faces?

27 identical drops of mercury are charged to the same potential of 10V . what will be the potential in all the charged drops are made to combine to form one large drop? Assume the drops to be spherical.

The binding energy per nucleon for $C^{12}$ is $7.68MeV$ and that for $C^{13}$ is $7.5MeV$. The energy required to remove a neutron from $C^{13}$ is

The potential energy of a body of mass $2\text{kg}$ in a conservative field is $U=(6x-8y)\text{J}$. If the initial velocity of body is $\overrightarrow{u}=(-1.5\hat{i}+2\hat{j})\text{m/s}$, then the total distance travelled by the particle in first two seconds is

Three rods of material x and two rods of material y are connected as shown in figure. All the rods are of identical length and cross – sectional area. The end A is maintained at ${100}^{\circ }C$ and the junction D at $0^{\circ }C$. It is given that resistance of rod of material x is R. Further, $K_x=2K_y$.



Match the entries of column I and column II
$\begin{array}{cc}Column-I& ColumnII\\ A.TemperatureofjunctionB& P.Doesnotbehavelikea\\ & balancedwheatston{e}^{\prime }sbridge\\ B.TemperatureofjunctionC& Q.Istwiceoftheother.\\ C.Thisnetworkis& R.\frac{400}{7}degreecelsius\\ D.Resistanceofrodofmaterialy& S.\frac{300}{7}degreecelsius\end{array}$

Three particles of masses $2\text{kg}$, $3\text{kg}$ and $5\text{kg}$ are placed at the three vertices $A,B,C$ of a right angled triangle respectively. Co-ordinates of the particles are $A(0,3),B(0,0)$ and $C(3,0)$. Find the position of centre of mass of the particles.

A block of mass m slides with a speed of $v_0=6\text{m/s}$ along a track from one level to a heigher level as shown. The track is frictionless until the block reaches the higher level where co-efficient of friction is $0.6$. The distance $d$ travelled by block on higher level before stopping is $(g=10{\text{m/s}}^2)$

Which of following statement is incorrect regarding ionization enthalpy:

The induced e.m.f in a coil is given by Є = 100πt sin volts. Calculate the number of rotations the coil makes per second

A stone is dropped from a 500 m tall building into a pond. When is sound of splash heard after the dropping of the stone? g = 10 $m/s^2$, speed of sound = 340 m/s

A sample of radioactive material decays simultaneously by two processes $A$ and $B$ with half lives $\frac{1}{2}$ h and $\frac{1}{4}$h, respectively. For the first half hour it decays with the process $A$, next one hour with the process $B$, and for further half an hour with both $A$ and $B$. If, originally there were $N_0$ nuclei, find the number of nuclei after 2 h of such decay.

List-I contains reactions and List-II contains reagents to effect the conversion.


Which of the following option is correct regarding List-I and List-II?

Two masses $m_1=5\text{kg},m_2=10\text{kg}$ connected by an inextensible massless string over a frictionless pulley, are released from rest as shown in the figure. The coefficient of static friction between the horizontal surface and block $m_2$ is $0.15$. The minimum mass $m$ in $\text{kg}$ that should be put on top of $m_2$ to stop the motion is

Stone A is projected from top of tower with speed $40\sqrt{2}m/s$ at an angle of ${45}^{\circ }$ with horizontal. At the same time stone B is projected from ground with speed $30m/s$ at an angle of ${30}^{\circ }$ with horizontal as shown.


Find the rate of change of relative velocity of A with respect to B after 1 second from the launch.

Two polaroids are oriented with their planes perpendicular to incident light and transmission axis making an angle of ${30}^{\circ }$ with each other. What fraction of incident unpolarised light is transmitted ?

A particle executes SHM on a straight line path. The amplitude of oscillation is 2 cm. When the displacement of the particle from the mean position is 1 cm, the numerical value of magnitude of acceleration is equal to the numerical value of magnitude of velocity. The time period of SHM (in Hz) is:

List I gives some physical quantites, and List II gives some possible graphs

symbols have usual meaning i.e., a, v, x, t stands for acceleration, velocity, position and time. For given v - t graph correct match is? Where at t = 0, particle is at some positive position

The figure shows current varying with time. The magnitude of constant direct current for a particular time which would produce same heat in identical resistance as produced by given varying current in the seconds.

A uniform rope of length $10\text{m}$ and mass $15\text{kg}$ hangs vertically from a rigid support. A block of mass $5\text{kg}$ is attached to the free end of the rope. A transverse pulse of wavelength $0.08\text{m}$ is produced at the lower end of the rope. The wavelength of the pulse when it reaches the top of the rope will be

The height at which the acceleration due to gravity becomes $g/9$ (where $g$ is acceleration due to gravity on the surface of the earth) in terms of the radius of the earth, $R$ is
(correct answer + 1, wrong answer - 0.25)

A uniform disc is spinning about geometrical axis in free space. If its temperature is increased by $\Delta T$, the fractional change in its angular velocity is ($\alpha$ is coefficient of linear expansion and $\alpha \Delta T<<1)$

The temperature inside and outside of the refrigerator is $260\text{K}$ and $315\text{K}$ respectively. Assuming that the refrigerator cycle is reversible, calculate the heat delivered to the surroundings for every joule of work done.

A wheel starting with angular velocity of $10\text{rad/sec}$ acquires angular velocity of $100\text{rad/sec}$ in $15\text{seconds}$. If angular acceleration of wheel is constant, what will be the angular displacement of the wheel in $15\text{seconds}$?

Which of the following relationships between the acceleration $a$ and the displacement $x$ of a particle implies simple harmonic motion?

As given in the figure two blocks $A$ & $B$ of weight $20\text{N}$ and $100\text{N}$ respectively are in equilibrium. These are being pressed against a wall by force $F$ as shown. If the coefficient of friction between the two blocks is $0.1$ and between block $B$ and the wall is $0.15$, the frictional force applied by wall on block $B$ is $\left(f_2\right)$ and the frictional force applied by block $B$ on block $A$ is $\left(f_1\right)$.

A 10kg block is kept on a horizontal surface and Ram is trying to pull it with a force of 5N, Given coefficient of static friction is 0.2 and coefficient of Kinetic friction n(μK) = 0.1 Which of these statements is/are correct.

For an adiabatic expansion of perfect gas $\frac{\Delta P}{P}$ is equal to:

The figure shows Billet split lens method to produce interference pattern on the screen. In this figure ‘S’ is a monochromatic point source emitting light of wavelength l = 500 nm. A thin lens of circular shape and focal length 0.10 m is cut into two identical halves $L_1$ and $L_2$ by a plane passing through a diameter. The two halves are placed symmetrically about the central axis SO with a gap of 0.5 mm. The distance along the axis from S to $L_1$ and $L_2$ is 0.15m, while that from $L_1$ and $L_2$ to O is 1.30 m. The screen at O is normal to SO.

If the gap between the two lenses $O_1{O}_2$ is reduced to half its initial value, then the fringe width of the interference pattern

A charged particle is projected with velocity υ₀ along positive x-axis. The magnetic field B is directed along negative z-axis between x = 0 and x = L. The particle direction of projection. Find the velocity with which the same particle is projected (at x = 0) along positive x - axis so that when it emerges out (at x = L), the angle made by it is 30⁰ with the direction of projection

A square of side 3cm is located at a distance 25 cm from a concave mirror of focal length 10cm. The centre of square is at the axis of the mirror and the plane is normal to axis of mirror. The area enclosed by the image of the square is:

A particle is moving in a circle and its angular velocity is given as $\omega =\pi t$ where $\omega$ is in radians and $t$ is in seconds. Find the average angular velocity at the end of one half circle.

how are frequency and wavelength related to each other

A seconds pendulum is moved to moon where acceleration due to gravity is $1/6$ times that of the earth, the length of the second pendulum on moon w.r.t length on earth would be:

Define the term intensity of a sound wave. State the unit in which it is measured.

A spherical soap bubble of radius $1\text{cm}$ is formed inside another of radius $3\text{cm}$. The radius of a single soap bubble which maintains the same pressure difference as inside the smaller and outside the larger soap bubble is

A block of mass $m\text{kg}$ is attached to a massless spring of spring constant $k\text{N/m}$. This system is accelerated upwards with an acceleration $a{\text{m/s}}^2$. Then the elongation in spring will be (in metres):

Two concentric coils each of radius equal to 2 $\pi$ cm are placed right angles to each other. If 3A and 4A are the currents flowing through the two coils respectively. The magnetic induction (in Wb m-2) at the center of the coils will be

Figure shows roughly how the force (F) between two adjacent atoms in a solid varies with separation (r)
(i) OQ is equilibrium separation
(ii) Hooke’s law is obeyed around P
(iii) The potential energy of the atom is the gradient of the graph at all points (iv) The energy to separate the atoms completely is obtained from the area enclosed below the axis of r

One mole of a monatomic gas undergoes the processes $1-2$ and $2-3$ as shown. The corresponding graph for the above processes if two moles of the gas is undertaken is

In equation $y=x^2{\cos }^{2}2\pi \frac{\beta \gamma }{\alpha }$, the units of $x,\alpha ,\beta$ are ${\text{m, s}}^{-1}$ and $(m{s}^{-1}{)}^{-1}$ respectively. The units of $y$ and $\gamma$ are