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The acceleration versus time graph of a particle is shown in figure. The respective $v–t$ graph of the particle is

An elevator car whose floor-to-ceiling distance is equal to 2.7 m starts ascending with constant acceleration 1.2 $m/s^2$. 2s after the start, a bolt begins falling from the ceiling of the car. Find:
(a) the bolt's free fall time;
(b) the displacement and the distance covered by the bolt during the free fall in the reference frame fixed to the ground.

In a school the physics teacher decides to perform an experiment in the lab. He left an ideal spring block system to do SHM an a frictionless table.

Five students are sent in the lab one by one and asked to write the equation of the SHM.

$Ram-{\Delta }_{0}sin(\omega t+\frac{\pi }{6})$

$Himanshu-{\Delta }_{0}sin(\omega t+\frac{2\pi }{3})$

$Satra-{\Delta }_{0}cos(\omega t+\frac{2\pi }{3})$

$Avinash-{\Delta }_{0}sin(\omega t+\frac{7\pi }{6})$

$Abhishek-{\Delta }_{0}sin(\omega t+\frac{5\pi }{6})$

Anand was asked to point out whose equations were in same phase and whose were in opposite phase?

(i)Ram and Avinash(x) same phase

(ii)Abhishek &Avinash(y) Opposite phase

(iii)Ram &Satra

Satra&Avinash

what will be the easiest definition of "Drift Velocity"?

When the temperature of a black body increases, it is observed that the wavelength corresponding to maximum energy changes from $0.26\mu \text{m}$ to $0.13\mu \text{m}$ Then ratio of the emissive power of the body at respective temperature is

A positive charge q is placed in front of a conducting solid cube at a distance d from its centre. Find the electric field at the centre of the cube due to the charges appearing on its surface.

A block of mass $0.1\text{kg}$ is held against a wall by applying a horizontal force of $5\text{N}$ on the block. If the coefficient of friction between the block and the wall is $0.5$, the magnitude of the friction force acting on the block is

During the melting of a slab of ice at 273 K at atmospheric pressure

Light of two different frequencies whose photons have energies 1 eV and 2.5 eV respectively, successively illuminate a metallic surface whose work function is 0.5 eV. Ratio of maximum speeds of emitted electrons will be

The end of a capillary tube with radius $r$ is immersed in water. Assuming the tube to be sufficiently long, calculate the heat energy produced when the water rises in the tube.
[Assume angle of contact = $0^{\circ }$ for glass-water system]
$\rho =$ density of water, $T=$ surface tension of water

Figure (32.E2) shows an arrangement to measure the emf $ϵ$ and internal resistance r of a battery. The voltmeter has a very high resistance and the ammeter also has some resistance. The voltmeter reads 1.52 V when the switch S is open. When the switch is closed the voltmeter reading drops to 1.45 V and the ammeter reads 1.0 A. Find the emf and the internal resistance of the battery.

Figure (32.E2)

A prism ‘X’ and another ‘Y’ are kept in contact with their refracting angles placed opposite to each other as shown in fig. White light is incident on the combination from the left. Column-I described some situation. Match Column-I with the possible out-comes given in Column-II

$\begin{array}{cccc}& \text{Column I}& & \text{Column II}\\ \text{(P)}& \text{The prisms are made of same material and their refracting}& \left(1\right)& \text{No deviation, No dispersion}\\ & \text{angles are equal,i.e A=A' The combination will cause}& & \\ \text{(Q)}& \text{The prisms are made of same material and their refracting}& \left(2\right)& \text{No deviation, Dispersion happens}\\ & \text{angles are not equal,i.e}A\ne A^{\prime }.\text{The combination will}& & \\ & \text{cause}& & \\ \text{(R)}& \text{The prisms are made of different material and their}& \left(3\right)& \text{No dispersion , deviation happens}\\ & \text{refracting angles are equal i.e.A=A'.Also the quantity}& & \\ & {\mu }_v-{\mu }_g\text{has different values for the two prisms. Here}& & \\ & {\mu }_{v}and{\mu }_g\text{are the refractive indices for violet and red}& & \\ & \text{colours. The combination will cause.}& & \\ \text{(S)}& \text{The prisms are made of different materials and their}& \left(4\right)& \text{Both deviation and dispersion}\\ & \text{refracting angles are unequal,}A\ne A^{\prime }.\text{Also}& & \text{happens}\\ & \frac{A}{A^{\prime }}=-\frac{({\mu }^{\prime }-1)}{(\mu -1)},\text{where}\mu \text{is the refractive index for the}& & \\ & \text{mean wavelength (yellow) for prism X while}{\mu }^{\prime }\text{is the}& & \\ & \text{corresponding value for prism Y. The combination will}& & \\ & \text{cause}& & \end{array}$

A 2g block attached to an ideal spring with a spring constant of 80N/m oscillates on a horizontal frictionless surface.When the spring is 4.0 cm shorter than its equilibrium length,the speed of 17^1/2m/s.The greatest speed of the block is

1)4m/s

2)6m/s

3)5m/s

4)9m/s

5)3m/s

Twelve resistor each of resistance 1W are connected in the circuit shown in figure. Net resistance between point A and H would be

A vertical $U$-tube is rotated about the vertical axis passing through the left limb, with an angular speed $\omega$ such that the liquid columns in the limbs have height $h$ and $3h$ where $h$ is $205mm$, as shown in figure. The value of $\omega$ (in $rad/s$) is (Take $g=10$ $m{s}^{-2}$)

Two particles are joined together by a string of total length $2L$ as shown in figure. Both the particles are performing uniform circular motion about point $\text{O}$ in a horizontal plane. If the speed of the outermost particle is $v_0$. Then the ratio of tension in string $\text{AB}$ and $\text{OA}$ will be:

A man of mass m is standing on a stationary wooden board of mass M kept on smooth ice. The man starts running on the board and acquires a speed u relative to the board. Find the speed of the man relative to stationary observer. The board is long enough.

The figure represents a closed cycle for the gas. The change in internal energy of the gas as it moves from $a$ to $c$ along path $abc$ is $-200\text{J}$. As it moves from $c$ to $d$, $180\text{J}$ must be transferred to it as heat, An additional transfer of $80\text{J}$ to it as heat is needed, as it moves from $d$ to $a$. How much work is done on the gas as it moves from $c$ to $d$ ?

Light with an energy flux of $25\times {10}^{4}W{m}^{-2}$ falls on a perfectly reflecting surface at normal incidence. If the surface area is $15c{m}^2$, the average force exerted on the surface is

Air is streaming past a horizontal air plane wing such that its speed in 120 m/s over the upper surface and 90 m/s at the lower surface. If the density of air is 1.3 kg per $metr{e}^3$ and the wing is 10 m long and has an average width of 2 m, then the difference of the pressure on the two sides of the wing of

A body of mass m, having momentum p is moving on a rough horizontal surface. If it is stopped in a distance $x$, the coefficient of friction between the body and the surface is given by:

A small particle of mass m = 2 kg moving with constant horizontal velocity u = 10 m/s strikes a wedge shaped block of mass M = 4 kg on its inclined surface as shown in figure. After collision particle starts moving up the inclined plane. Calculate the velocity of wedge immediately after collision. ___

On a $P-T$ diagram, a cyclic process is performed as shown. Where is the volume maximum?

In which frequency range, space waves are normally propagated

In parallex method, we observe a star at a particular point from earth, till the time we reach diametrically opposite point on earth's orbit does that star remain at that point and at second observation there are too many stars how do we came to know, which star we measured before?

In the given situation, two blocks A and B are arranged as shown in the figure. M is a fixed pulley and N is a movable pulley. The system is released from rest. What is the relationship between accelerations for the blocks A and B?

Choose the word which is most opposite in meaning to the word as used in the passage:

Locomotion

Calculate the area of the parallelogram when adjacent sides are given by the vectors $\overrightarrow{A}=\hat{i}-\hat{j}+2\hat{k}$ and $\overrightarrow{B}=2\hat{i}-3\hat{j}+4\hat{k}$

Differentiation of $\sin x^2$ w.r.t. $x$ is

If the mean free path of atoms is doubled then the pressure (P) of gas will become

The ends of a stretched wire of length $L$ are fixed at $x=0$ and $x=L$. If in an experiment, the displacement of the wire is $y_1=A\sin \left(\frac{\pi x}{L}\right)\sin \omega t$ and energy is $E_1$ and in another experiment, its displacement is $y_2=A\sin \left(\frac{2\pi x}{L}\right)\sin 2\omega t$ and energy is $E_2$, then
[Assume, there is no energy loss at the ends of the stretched wire]

Two identical pith balls are charged by rubbing against each other. they are suspended from a horizontal rod through two strings of length 20 cm each, the separation between the suspension points being 5 cm. In equilibrium, the sepaation between the balls is 3 cm. Find the mass of each ball and the tension in the stirngs. The charge on each ball ahs a magnitude $2.0\times {10}^{-8}$ C.

A ball of mass $m$ moving with a speed $u$ collides elastically with another identical ball moving with velocity $u_2$. Find the angle between velocities after collision if they collide obliquely and $u_2$ = 0​

A water wave traveling in a straight line on a lake is described by the equation.

$y(x,t)=3.75cmcos(0.450c{m}^{-1}x+5.40s^{-1}t)$

where y is the displacement perpendicular to the undisturbed surface of the lake. How much time does it take for one complete wave pattern to go past a fisherman in a boat at anchor?

For the velocity-time graph shown in figure, in a time interval from $t=0$ to $t=6\text{s}$, match the following

$\begin{array}{cc}\text{Table-1}& \text{Table-2}\\ \text{(A) Change in velocity}& \text{(P)}-\frac{5}{3}\text{SI unit}\\ \text{(B) Average acceleration}& \text{(Q)}-20\text{SI unit}\\ \text{(C) Total displacement}& \text{(R)}-10\text{SI unit}\\ \text{(D) Acceleration at}t=3\text{s}& \text{(S)}-5\text{SI unit}\end{array}$

Figure shown plane figure made of a conductor located in a magnetic field along the inward normal to the plane of the figure. The magnetic field starts diminishing. Then the induced current

An inductor of inductance $L=400mH$ and resistors of resistance $R_1=2\Omega ,R_2=2\Omega$ are connected to a battery of e.m.f $E=12V$ as shown in the figure. The internal resistance of the battery is negligible. The switch $S$ is closed at $t=0$. The potential drop across $L$ as a function of time is

A slender uniform rod of mass $M$ and length $l$ is pivoted at one end so that it can rotate in a vertical pane (see figure). There is negligible friction at the pivot. The free end is held vertically above the pivot and then released. The angular acceleration of the rod when it makes an angle $\theta$ with the vertical is

An electron of mass $m$ with an initial velocity $\overrightarrow{v}=v_0\hat{i}$ $(v_0>0)$ enters an electric field $\overrightarrow{E}=E_0\hat{i}$ ($E_0$ = constant) at $t=0$. If ${\lambda }_0$ is its De-Broglie wavelength initially, then its De-Broglie wavelength at time $t$ is

The radioactivity of a sample is $R_1$ at time $T_1$ and $R_2$ at time $T_2$ . If the half life of the specimen is $T$, number of atoms that have disintegrated in time $(T_2-T_1)$ is proportional to

A space of elastic material is taken to bottom of sea (1 km deep). If radius changes by 0.02%, then the bulk modulus of elasticity of material is (Excess pressure = $\rho$gh)