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Explain why the reactance provided by a capacitor to an alternating current decreases with increasing

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What will be its, reactance when connected in DC circuit? What is its

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A toroid has a core (non-ferromagnetic) of inner radius 25 cm and outer radius 26 cm, around which 3500 turns of a wire are wound. If the current in the wire is 11 A, what is the magnetic field(i) outside the toroid,(ii) inside the core of the toroid, (iii) in the empty space surrounded by the

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The diagrams given in Fig. show magnetic field lines (thick lines in the figure) wrongly. Point out what is wrong with them.

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The diagrams given in Fig. show magnetic field lines (thick lines in the figure) wrongly. Point out what is wrong with them.

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

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The diagrams given in Fig. show magnetic field lines (thick lines in the figure) wrongly. Point out what is wrong with them.

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

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A short bar magnet of magnetic movement 5.25 × 10–2 J T –1 is placed with its axis perpendicular to the earth’s field direction. At what distance from the centre of the magnet, the resultant field is inclined at 45° with earth’s field on(i) its normal bisector (ii) its axis. Magnitude of the earth’s field at the place is given to be 0.42 G. Ignore the length of the magnet in comparison to the distances

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

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A Rowland ring of mean radius 15 cm has 3500 turns of wire wound on a ferromagnetic core of relative permeability 800. What is the magnetic field B in the core for a magnetising current of 1.2

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

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Three identical bar magnets are rivetted together at centre in the same plane as shown in Fig. This system is placed at rest in a slowly varying magnetic field. It is found that the system of magnets does not show any motion. The north-south poles of one magnet is shown in the Fig. Determine the poles of the remaining

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Verify the Ampere’s law for magnetic field of a point dipole of dipole moment` m = mhatk` . Take C as the closed curve running clockwise along along the quarter circle of radius R and centre at the origin, in the first quadrant of x-z

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The gyro-magnetic ratio of an electron in an H-atom, according to Bohr model,

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A 100 turn rectangular coil ABCD (in XY plane) is hung from one arm of a balance (Fig). A mass 500g is added to the other arm to balance the weight of the coil. A current 4.9 A passes through the coil and a constant magnetic field of 0.2 T acting inward (in xz plane) is switched on such that only arm CD of length 1 cm lies in the field. How much additional mass ‘m’ must be added to regain the

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A proton and an particle are projected with the same kinetic energy at right angles to the uniform mag. field. Which one of the following statements will be

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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,

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An infinitely long hollow conducting cylinder with inner radius `R/2` and outer radius R carries a uniform current density along its length. The magnitude of the magnetic field `|vecB|` as a function of the radial distance r from the axis is best represented

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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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Dielectrics Dielectrics are insulating (non-conducting) materials that can produce electric effect without conduction. Movement of free charges is not possible in a dielectric, so they behave differently.When a dielectric material is kept in an electric field, then the external field induces dipole moment. Due to which, net charges on the surface of the dielectric appears.The SI unit of dielectric strength

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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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Commercial Electrical EnergyAn electrical appliance uses a lot of electric energy when it is operated e.g., geysers heaters etc. The electrical energy consumed is dependent on the time for which a specific appliance of fixed power rating is used. However, the energy used in hour is denoted as `1 kWh=3.6 xx 10^6` joule. This is represented as 1 unit. Different electrical appliance have difference power consumption which is mentioned on the device clearly.The wires used in heating element are different than the connecting wires. The connecting wires uses copper but heating element does not

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

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