Answers by kritika

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A fighter plane, flying horizontally with a speed \(360 \mathrm{kmph}\) at an altitude of \(500 \mathrm{~m}\) drops a bomb for a target straight ahead of it on the ground. The bomb .should be dropped at what approximate distance ahead of the target ? Assume that acceleration due to gravity \((\mathrm{g})\) is \(10 \mathrm{~ms}^{-2}\). Also neglect air drag

answered Dec 16, 2021 in Kinematics

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The bob of a swinging seconds pendulum (one whose time period is \(2 \mathrm{~s}\) ) has a small speed \(\mathrm{v}_{0}\) at its lowest point. Its height from this lowest point \(2.25 \mathrm{~s}\) after passing through it is given by

answered Dec 15, 2021 in Kinematics

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Four identical point masses, each of mass \(m\) and carrying charge \(+q\) are placed at the corners of a square of sides 'a' on a frictionless plain surface. If the particles are released simultaneously, the kinetic energy of the system when they are infinitely far apart is

answered Dec 15, 2021 in Kinematics

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A galvanometer can be converted to a voltmeter of full-scale deflection \(V_{0}\) by connecting a series resistance \(R_{1}\) and can be converted to an ammeter of full-scale deflection \(I_{0}\) by connecting a shunt resistance \(R_{2}\). What is the current flowing through the galvanometer at its full-scale deflection ?

answered Dec 15, 2021 in Kinematics

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A conducting circular loop of resistance \(20 \Omega\) and cross-sectional area \(20 \times 10^{-2} \mathrm{~m}^{2}\) is placed perpendicular to a spatially uniform magnetic field \(B\), which varies with time \(t\) as \(B=2 \sin (50 \pi t) T\). Find the net charge flowing through the loop in \(20 \mathrm{~ms}\) starting from \(\mathrm{t}=0\)

answered Dec 15, 2021 in Magnetic effects of

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Consider an engine that absorbs 130 cal of heat from a hot reservoir and delivers 30 cal heat to a cold reservoir in each cycle. The engine also consumes \(2 \mathrm{~J}\) energy in each cycle to overcome friction. If the engine works at 90 cycles per minute, what will be the maximum power delivered to the load? [Assume the thermal equivalent of heat is \(4.2 \mathrm{~J} / \mathrm{cal}\) ]

answered Dec 15, 2021 in Kinematics

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A point source of light is used in an experiment of photo-electric effects. If the distance between the source and the }{ photo-electric surface is doubled, which of the following may result? }

answered Dec 15, 2021 in Kinematics

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Two metallic spheres of equal outer radii are found to have same moment of inertia about their respective diameters. Then which of the following statement(s) is/are true ?

answered Dec 15, 2021 in Kinematics

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A \(400 \Omega\) resistor, a \(250 \mathrm{mH}\) inductor and a \(2.5 \mu \mathrm{F}\) capacitor are connected in series with an \(\mathrm{AC}\) source of peak voltage \(5 \mathrm{~V}\) and angular frequency \(2 \mathrm{kHz}\). What is the peak value of the electrostatic energy of the capacitor?

answered Dec 15, 2021 in Kinematics

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If Young's double slit experiment is done with white light, which of the following statements will be true?

answered Dec 15, 2021 in Kinematics

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How the linear velocity 'v' of an electron in the Bohr orbit is related to its quantum number ' \(n\) ' ?

answered Dec 15, 2021 in Kinematics

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If the half life of a radioactive nucleus is 3 days, nearly what fraction of the initial number of nuclei will decay on the \(3^{\text {rd }}\) day? (Given that \(\sqrt[3]{0.25} \approx 0.63\) )

answered Dec 15, 2021 in Kinematics

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An electron accelerated through a potential of \(10,000 \mathrm{~V}\) from rest has a de-Broglie wave length ' \(\lambda\) '. What should be the accelerating potential so that the wave length is doubled?

answered Dec 15, 2021 in Kinematics

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In case of a simple harmonic motion, if the velocity is plotted along the X-axis and the displacement (from the equilibrium position) is plotted along the Y-axis, the resultant curve happens to be an ellipse with the ratio: \(\frac{\text { major axis (along X) }}{\text { min or axis (along Y) }}=20 \pi\) What is the frequency of the simple harmonic motion ?

answered Dec 15, 2021 in Kinematics

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The velocity \((v)\) of a particle \((\) under a force \(F)\) depends on its distance \((x)\) from the origin \((\) with \(x>0) v \propto \frac{1}{\sqrt{x}} .\) Find how the magnitude of the force \((F)\) on the particle depends on \(x\)

answered Dec 15, 2021 in Kinematics

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The ratio of accelerations due to gravity \(\mathrm{g}_{1}: \mathrm{g}_{2}\) on the surfaces of two planets is \(5: 2\) and the ratio of their respective average densities \(\rho_{1}: \rho_{2}\) is \(2: 1\). What is the ratio of respective escape velocities \(v_{1}: v_{2}\) from the surface of the planets?

answered Dec 15, 2021 in Kinematics

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A spherical liquid drop is placed on a horizontal plane. A small disturbance causes the volume of the drop to oscillate. The time period of oscillation \((T)\) of the liquid drop depends on radius \((r)\) of the drop, density \((\rho)\) and surface tension (s) of the liquid. Which among the following will be a possible expression for \(\mathrm{T}\) (where \(\mathrm{k}\) is a dimensionless constant) ?

answered Dec 15, 2021 in Kinematics

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The stress along the length of a rod (with rectangular cross section) is \(1 \%\) of the Young's modulus of its material. What is the approximate percentage of change of its volume? (Poisson's ratio of the material of the rod is \(0.3\) )

answered Dec 15, 2021 in Kinematics

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What will be the approximate terminal velocity of a rain drop of diameter \(1.8 \times 10^{-3} \mathrm{~m}\), when density of rain water \(\approx 10^{3}\) \(\mathrm{kgm}^{-3}\) and the co-efficient of viscosity if air \(\approx 1.8 \times 10^{-5} \mathrm{Nsm}^{-2}\) ? (Neglect buoyancy of air)

answered Dec 15, 2021 in Kinematics

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One mole of a mono-atomic ideal gas undergoes a quasi-static process, which is depicted by a straight line joining points \(\left(\mathrm{V}_{0}, \mathrm{~T}_{0}\right)\) and \(\left(2 \mathrm{~V}_{0}, 3 \mathrm{~T}_{0}\right)\) in a V-T diagram. What is the value of the heat capacity of the gas at the point \(\left(\mathrm{V}_{0}, \mathrm{~T}_{0}\right) ?\)

answered Dec 15, 2021 in Kinematics

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