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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

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

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Magnetic Field of a SolenoidMohan tightly wound a very long copper wire on a PVC pipe and carefully took the pipe out. The two ends of the copper wire then attached to a battery. This cylindrical shape of copper wire showed few properties of a bar magnet. Later he found that it is called a solenoid and this solenoid is used in several devices such as door bell, relay switch etc. The magnetic field of a solenoid is given below.The magnetic field strength of a solenoid having n turns is `B=mu_0nl`, where, `I` is the current flowing in the solenoid.The

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At a place in magnetic meridian, magnetic needle bends 30° from horizontal. If earth’s magnetic field at this place is 2 G, then vertical component and horizontal component of earth’s magnetic field respectively,

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Same current is flowing in two alternating circuits. The first circuit contains only inductance and the other contains only a capacitor. If the frequency of the emf of AC is increased, the effect on the value of the

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An L-C-R circuit contains `R=50 Omega, L=1 mH and C = 0.1 muF`. The impedance of the circuit will be minimum for a frequency

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Assertion: Inductive reactance of an inductor in DC circuit is zero. Reason: Angular frequency of DC circuit is

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Assertion: If an inductor coil is connected to DC source, the current supplied by it is `I_1`.If the same coil is connected with an AC source of same voltage. Then, current is `I_2`. Then, `I_2 < I_1.` Reason: In AC circuit, inductor coil offers more

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Electrical ResonanceElectrical resonance is said to take place in a series L-C-R circuit when the circuit allows maximum current for a given frequency of the source of alternating supply for which capacitive reactance becomes equal to the inductive reactance. Impedance of this L-C-R circuit is minimum and hence current is maximum. Resonant circuits are used to respond selectively to signals of a given frequency while discriminating against signals of different frequencies. If the response of the circuit is more narrowly peaked around the chosen frequency, we say that the circuit has higher “selectivity or sharpness”. This sharpness is measures with

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AC Generator An AC generator produces electrical energy from mechanical work, just the opposite of what a motor does. In it, a shaft is rotated by some mechanical means, such as an engine or a turbine starts working and an emf is induced in the coil.It is based on the phenomenon of electromagnetic induction which states that whenever magnetic flux linked with a conductor (or coil) changes, an emf is induced in the coil. Which method is used to induce an emf or current in a loop in AC

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Use the mirror equation to deduce that: an object placed between the pole and focus of a concave mirror produces a virtual and enlarged image. [Note: This exercise helps you deduce algebraically properties of images that one obtains from explicit ray

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A small pin fixed on a table top is viewed from above from a distance of 50cm. By what distance would the pin appear to be raised if it is viewed from the same point through a 15cm thick glass slab held parallel to the table? Refractive index of glass = 1.5. Does the answer depend on the location of the

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Explain: When viewing through a compound microscope, our eyes should be positioned not on the eyepiece but a short distance away from it for best viewing. Why? How much should be that short distance between the eye and

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A biconvex lens made of a transparent material of refractive index 1.25 is immersed in a water of refractive index 1.33. Will the lens behave as a- converging or a diverging lens? Give

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State the criteria for the phenomenon of total internal reflection of light to take

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Light incident at an angle of incidence of 45° in a certain medium goes grazing along its surface of separation from air after refraction. What is (i) the velocity of light in this medium? (ii) the angle of incidence at which light from air must be incident on this medium so that the refracted ray is normal to the reflected ray? Also, name the special property exhibited by light for this angle of

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A convex lens of focal length 25 cm is placed coaxially in contact with a concave lens of focal length 20 cm. Determine the power of the combination. Will the system be converging or diverging in

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(i) Draw a labelled ray diagram showing the image formation of a distant object by refracting telescope. Deduce the expression for its magnifying power when the final image is formed at infinity. (ii) The sum of focal lengths of the two lenses of a refracting telescope is 105 cm. The focal length of one lens is 20 times that of the other. Determine the total magnification of the telescope when the final image is formed at

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Is the speed of light in glass independent of the colour of light? If not, which of the two colours red and violet travels slower in a glass

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The wavelength of light from the spectral emission line of sodium is 589 nm. Find the kinetic energy at which(i) an electron, (ii) a neutron, would have the same de Broglie

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(i) A monoenergetic electron beam with electron speed of 5.20 × 106 m s–1 is subject to a magnetic field of 1.30 × 10–4 T normal to the beam velocity. What is the radius of the circle traced by the beam, given e/m for electron equals 1.76 × 1011C kg–1 .(ii) Is the formula you employ in (i) valid for calculating radius of the path of a 20 MeV electron beam? If not, in what way is it modified? [Note: Exercises 20(ii) and 21(ii) take you to relativistic mechanics which is beyond the scope of this book. They have been

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

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