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Two particles A and B of masses `m_A` and `m_B` respectively and having the same charge are moving in a plane. A uniform mag. field exists perpendicular to this plane. The speeds of the particles are `V_A` and `V_B` respectively and the trajectories are as shown in the figure,

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

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A conducting rod of length ? [cross-section is shown] and mass m is moving down on a smooth inclined plane of inclination `theta` with constant speed `v` . A vertically upward mag. field `vecB` exists in upward direction. The magnitude of mag. field `vecB` is

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A Galvanometer of resistance `50Omega` is connected to a battery of 3 volt along with a resistance of `2950Omega` in series. A full scale deflection of 30 divisions is obtained in the galvanometer. In order to reduce this deflection to 20 divisions, the resistance in series should

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A Galvanometer coil has a resistance of `15Omega` and gives full scale deflection for a current of 4 mA. To convert it to an ammeter of range 0 to 6

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

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A conducting circular loop of radius a carries a constant current I. It is placed in a uniform magnetic field `vecB`, such that `vecB` is perpendicular to the plane of the Loop. The magnetic force acting on the Loop is

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The variation of magnetic suceptibility `(chi)` with mognetising field for a paramognetic substance

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The most appropriate magnetization `Mto` magnetising field H curve for a paramagnetic substance

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A comb runs through one’s dry hair attracts small bits of paper. This happens

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Forces exerted by a uniform electric field on an electron having mass `m_e` and proton of mass `m_p` are represented as `F_e and F_p` respectively are related

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A parallel plate air capacitor has a capacitance `18 muF`. If the distance between the plates is tripled and a dielectric medium is introduced, the capacitance becomes `72 muF`. The dielectric constant of the medium

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The figure below shows a `2.0 V` potentiometer used for the determination of internal resistance of a `2.5 V` cell. The balance point of the cell in the open circuit is 75 cm. When a resistor of `10 Omega` is used in the external circuit of the cell, the balance point shifts to 65 cm length of potentiometer wire. The internal resistance of the cell

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Resistance and Resistivity The materials can be classified as conductors, semiconductors and insulators depending on their resistivities, in an increasing order of their values. Metals have low resistivities in the range of `10^(-8)Omegam` to `10^(-6)Omegam`. At the other end are insulators like ceramic, rubber and plastics having resistivities `10^(18)` times greater than metals or more. In between these two are the semiconductors. These however, have resistivities characteristically decreasing with a rise in temperature. The resistivities of semiconductors can be decreased by adding small amount of suitable impurities. This last feature is exploited in use of semiconductors for electronic devices.Commercially produced

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EMF of a CellAn electric cell is a source of energy that maintains a continuous flow of charge in a circuit. It changes chemical energy into electrical energy. It has two electrodes, positive electrode and negative electrode as shown below.Electric cell has to do some work in maintaining the current through a circuit. The work done by the cell in moving unit positive charge through the whole circuit (including the cell) is called the electromotive force (emf) of the cell. The current flowing in the cell

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Wheatstone Bridge In 1845 by German physicist Gustav Kirchhoff described Kirchhoff’s circuit laws which are two equalities that deal with the current and potential difference (commonly known as voltage) in the lumped element model of electrical circuits.As an application of these laws, consider the circuit shown below, which is called the Wheatstone bridge. This bridge consists of four resistors `R_1, R_2, R_3 and R_4`. Across one pair of diagonally opposite points (A and C in the figure) a source is connected.This (i.e., AC) is called the battery arm. Between the other two vertices, B and Z), a galvanometer G (which

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Electron Moving in Magnetic Field An electron with a speed `v_0 ( < < c)` moves in a circle of radius `r_0`, in a uniform magnetic field. This electron is able to travel in a circular path as magnetic field is perpendicular to the velocity of the electron. The time required for one revolution of the electron is `T_0`. The speed of the electron is now, doubled to `2v_0`.If the given electron has a velocity not perpendicular to B, then the trajectory of the electron

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Lorentz Force and Its Effects A charged particle moving in an external magnetic field experiences a force, which is called Lorentz force, i.e. `F=q(v xx B)`,where `q` is the charge on the particle and v is the velocity of the particle. The direction of the force is given by the cross product of velocity vector and magnetic field vector at any time.The charge particle travels in a special trajectory called helical path. Because the force is always perpendicular to the velocity vector, the magnetic field can do no work on an isolate charge. Hence, the linear velocity always remains the

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Moving Coil GalvanometerMoving coil galvanometer operates on Permanent Magnet Moving Coil (PMMC) mechanism and was designed by the scientist D’arsonval.Moving coil galvanometers are of two types (i) Suspended coil (ii) Pivoted coil type or tangent galvanometer.Its working is based on the fact that when a current carrying coil is placed in a magnetic field, it experiences a torque. This torque tends to rotate the coil about its axis of suspension in such a way that the m agnetic flux passing through the coil is maximum .The deflection in a moving coil galvanometer

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Assertion: Basic difference between an electric line and magnetic line of force is that former is discontinuous and the latter is continuous or endless. Reason: No electric lines of forces exist inside a charged conductor but magnetic lines do exist inside a

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Earth’s Magnetic FieldThe magnetic field lines of the earth resemble that of a hypothetical magnetic dipole located at the centre of the earth. The axis of the dipole is presently tilted by approximately 11.3° with respect to the axis of rotation of the earth.The pole near the geographic north pole of the earth is called the north magnetic pole and the pole near the geographic south pole is called south magnetic pole.The strength of the earth’s magnetic field varies from place-to-place on the earth’s surface, its value being of the order

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Amongst the following physical parameter, which is equivalent to

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

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