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Two coils of self inductances 2 mH & 8 mH are placed so close togather that the effective flux in one coil is completely half with the other.The mutual inductance between these coils

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

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Find out reading of A C ammeter and also calculate the potential difference across, resistance and

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Match the Column I (graph) with Column II (relation) and select the correct answer from the codes given below. Column I Column II A. p. Temperature dependence of resistivity for a typical semiconductor. B. q. Resistivity p of copper as a function of temperature T. C. r. Resistivity `rho` of nichrome as a function of absolute temperature T .

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

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(i) Estimate the speed with which electrons emitted from a heated emitter of an evacuated tube impinge on the collector maintained at a potential difference of 500 V with respect to the emitter. Ignore the small initial speeds of the electrons. The specific charge of the electron, i.e., its e/m is given to be 1.76 × 1011 C kg–1 .(ii) Use the same formula you employ in (i) to obtain electron speed for an collector potential of 10 MV. Do you see what is wrong ? In what way is the formula to be

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

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The electric potential in a region is given by the relation `V(x) = 4 + 5x^2` . If a dipole is placed at position (–1,0) with dipole moment `vecp` pointing along positive Y-direction,

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

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Consider a system of three charges `q/3, q/3 and –2a/3` placed at points A, B and C respectively as shown in the figure. It the radius of the circle is R and `/_CAB = 60^o` then the electric field at centre 0 is ........

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

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Two capillary tubes of length 15 cm and 5 cm and radii 0.06 cm and 0.02 cm respectively are connected in series. If the pressure difference a cross the end faces is equal to the pressure of 15 cm high water column, then find the pressure difference across the : → 1) first tube 2) Second

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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According to additive property of charges

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

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Study the circuits (a) and (b) shown in Fig and answer the following questions. Can the rms current in circuit (b) be larger than that in

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

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A circular coil of 500 turns encloses an area of `0.04 m^2`. A uniform magnetic field of induction `0.25 Wb'/'m^2` is applied perpendicular to the plane of the coil. The coil is rotated by 90° in 0.1 second at a constant angular velocity about one of its diameters. A galvanometer of resistance `25Omega` was connected in series with the the coil. The total charge that will pass through the galvanometer is

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

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(i) Draw a ray diagram for formation of image of a point object by a thin double convex lens having radii of curvatures `R_1 and R_2` and hence, derive lens maker's formula. (ii) Define power of a lens and give its SI unit. If a convex lens of length 50 cm is placed in contact coaxially with a concave lens of focal length 20 cm, what is the power of the

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

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Define magnifying power of a telescope. Write its expression. A small telescope has an objective lens of focal length 150 cm and an eyepiece of focal length 5 cm. If this telescope is used to view a 100 m high tower 3 km away, find the height of the final image when it is formed 25 cm away from the

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

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When monochromatic light is incident on a surface separating two media, the reflected and refracted light both have the same frequency as the incident frequency. Explain

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

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An early model for an atom considered it to have a positively charged point nucleus of charge Ze, surrounded by a uniform density of negative charge up to a radius R. The atom as a whole is neutral. For this model, what is the electric field at a distance r from the

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

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A point positive charge is brought near an isolated conducting sphere (Fig. 1.2). The electric field is best given

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

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Consider a sphere of radius R with charge density distributed as `ρ (r ) = kr ' for ' r le R` `ρ (r ) =0 ' for ' r > R` . (i) Find the electric field at all points r.(ii) Suppose the total charge on the sphere is 2e where e is the electron charge. Where can two protons be embedded such that the force on each of them is zero. Assume that the introduction of the proton does not alter the negative charge

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

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There are two coils A and B as shown in Fig A current starts flowing in B as shown, when A is moved towards B and stops when A stops moving. The current in A is counterclockwise. B is kept stationary when A moves. We can infer

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

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A magnetic field `2xx 10^(-2) T` acts at right angles to a coil of area `200 cm^2` with 25 turns. The average emf induced in the coil is 0.1 v when it removes from the field in time t. The value of t

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

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When a train travels with a speed `360 km h^(-1)` along the track separated by 1 meter. The vertical component of earth's magnetic field is `0.1xx 10^(-4) T` .What is the value of induced emf between the rails

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

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If `E=20 sin (100pit)` volt then calculate value of E at `t=1/600

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

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