Recent questions tagged physics-and-measurement

Six equal resistance are connected between point P,Q,R as shown in the fig. Then the net resistance will be maximum between

asked Feb 8, 2016 by meena.p

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A solenoid carrying a current supplied by a DC source with constant emf contains iron rod inside it. when the rod is pulled out of the solenoid , then the current in the solenoid will

asked Feb 8, 2016 by meena.p

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In an AC circuit V and I are given by $V=100 \sin (100 t) volt \; I =100 \sin (100 t +\large\frac{\pi}{3})amp$ the power dissipated in the circuit is

asked Feb 8, 2016 by meena.p

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An aeroplane is moving north horizontally , with a speed of $200 ms^{-1}$ ,at a place where the vertical component of the earth's magnetic field is $ 0.5 \times 10^{-4}\;T$ .What is the induced e.m.f set up between the tips of the wings, if they are 10 m apart ?

asked Feb 8, 2016 by meena.p

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If vectors $\overrightarrow{A} = \cos wt \hat i +\sin w + \hat j$ and $\overrightarrow{B} = \cos wt/2 \hat i +\sin wt/2 + \hat j$ are functions of time , then the value of t at which are orthogonal to each other is

asked Feb 8, 2016 by meena.p

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A child is standing with his two arms outstretched at the center of a turntable that is rotating about its central axis with an angular speed $w_0$ Now the child folds his hands back so that the moment of inertia becomes 3 times the intial values.The new angular speed is

asked Feb 8, 2016 by meena.p

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Three planets of same density and with radii $R_1,R_2$ and $R_3$ Such that $R_1=2R_2=3R_3$, have gravitational fields on the surfaces $E_1,E_2,E_3$ and escape velocities $v_1,v_2,v_3$ respectively ,then

asked Feb 8, 2016 by meena.p

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A block of wood floats in water with $\large\frac{4}{5}$ th of its volume submerged , but it just floats in a liquid . What is the density of the liquid ?

asked Feb 8, 2016 by meena.p

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A clock with an iron pendulum beeps correct time at $15 ^{\circ}c$ what will be the error in time per day , if the room temperature is $20^{\circ}$?

asked Feb 8, 2016 by meena.p

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A charge q is placed at the centroid of an equilateral triangle. Three charges equal to Q are placed at the vertices of the triangle . The system of the four charges will be in equilibrium . if q is equal to

asked Feb 8, 2016 by meena.p

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Two H atoms in the ground state collide elastically. The maximum amount by which their combined kinetic energy reduced is

asked Feb 8, 2016 by meena.p

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The total energy in the ground state of hydrogen atom is $ -13.6\;eV$ . The kinetic energy of this electron in first excited state is :

asked Feb 8, 2016 by meena.p

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Ina common emitter configuration, a transistor have $\beta= 50$ and input resistance $1k \omega$ . If the peak value of a.c input is $0.01\;V$ then the peak value of collector current is

asked Feb 8, 2016 by meena.p

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A ratio station has two channels . one is AM at $1020 kHz$ and the other FM at $89.5$ MHz. For good results you will use

asked Feb 8, 2016 by meena.p

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A ball is dropped to the ground from a height of 8 m. The coefficient of restitution is 0.5 . To what height will the ball rebound?

asked Feb 8, 2016 by meena.p

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An astronaut is looking down on Earth's surface from a space shuttle at an attitude of 400 km. Assuming that the assonants pupil diameter is 5 mm and wave length of visible light is 500 nm, the assonant will be able to resolve linear objects of the size of about

asked Feb 8, 2016 by meena.p

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The second overtone of an openpipe has the same frequency as the first overtone of a closed pipe 2m long . Calculate the length of the open pipe .

asked Feb 8, 2016 by meena.p

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A horizontal platform with an object placed on it is executing is $3.92 \times 10^{-3}$ what must least period of these oscillation , So that the object is not detached from the platform?

asked Feb 8, 2016 by meena.p

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A parallel plate capacitor c with plates of unit area and separation d is filled with a liquid of dielectric constant $k=2$ The level of the liquid is$\large\frac{d}{3}$ initially . Suppose the liquid level decreases at constant speed V, the time constant as a function of time t is

asked Feb 8, 2016 by meena.p

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The work done in turning a magnet of magnetic moment by an angle of $90^{\circ}$ from the meridian is n times the corresponding work done to turn it through an angle of $60^{\circ}$ . The value of n is given by

asked Feb 8, 2016 by meena.p

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A conductivity loop in the form of a circle is placed in a uniform magnetic field with its plane perpendicular to the direction of the field. An e.m.f will be included in the loop if

asked Feb 8, 2016 by meena.p

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An objects is located 4 m from the first of two thin covering lenses of focal length 2 m and respectively . The lenses are separated by 3 m. The final image formed by the second less is located from the source ata distance if :

asked Feb 8, 2016 by meena.p

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A Tv transmitting antenna is $128$ m tall. If the reactivating antenna is at the ground level, the maximum distance between them for satisfactory communication is LOS mode is (R of earth $=6.4 \times 10^6 m)$

asked Feb 8, 2016 by meena.p

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A person carrying a whistle entitling continuously a note of 272 Hz is running towards a reflecting surface with a speed of $18 km h^{-1}$. The speed of sound in air is $345 ms^{-1}$ The number of beats heard by him is

asked Feb 8, 2016 by meena.p

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In the circuit shown in the fig the battery is ideal. A voltmeter of resistance $600 \Omega$ is connected in turn across $R_1$ and $R_2$ , giving reading $V_1$ and $V_2$ respectively . Then

asked Feb 8, 2016 by meena.p

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Two deuterium nuclei each of mass m, fuse together to form a helium nucleus , releasing an energy E. If C is the velocity of light , the mass of helium nucleus formed will be

asked Feb 8, 2016 by meena.p

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A boat which has a speed of $5\;kmh^{-1}$ in still water crosses a river of width 1 km along the shortest possible path in 15 mints . The velocity the river water in $kmh^{-1} $ is

asked Feb 8, 2016 by meena.p

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A resister of $500 \Omega$ an inductance of $0.5$ H are in series with an ac which is given by $v= 100 \sqrt 2 \sin (1000 t)$. The passer factor of the combination is :

asked Feb 8, 2016 by meena.p

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The base current of transistor is $100 \mu A$ and the collector current is $2mA$ . What is the current gain for the common base configuration ?

asked Feb 8, 2016 by meena.p

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The moment of inertia of the system of four spheres about the side AD, when four solid spheres each of mass m and radius r are located with their centers on four corners of a square ABCD of slide a is :

asked Feb 8, 2016 by meena.p

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The type of isomerism found in vrea molecule is

asked Apr 15, 2015 by meena.p

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