Capacitance of spherical capacitor with mixed dielectrics: Let us consider A and B are the two concentric spherical shells of radii a and b respectively (b >a). Shell A is charged by Q and the outer surface of shell B is earthed. Let a shell filled with dielectric medium of dielectric constant K2 of inner […]
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A capacitor has rectangular plates of length a and width b. The top plate is inclined at a small angle . Find the capacitance of the capacitor. Let us consider the given capacitor is made of large number of elementary capacitors connected in parallel. Let an elementary capacitor of width dx at a distance x
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Charging and discharging of a capacitor: Charging: Let us consider a capacitor C is connected to a battery of emf E through a resistance R. During charging of the capacitor the potential difference across the plates becomes equal to the emf of the battery. Let at any time t, I is the current through the
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Capacitance due to variable electric field: If the two conductors A and B carry equal and opposite charges create a non-uniform electric field then find the capacitance of the system. The distance between the conductors is d. If Q is the charge of each conductor and electric field E = (a + by) varies along
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Kirchhoff’s law for capacitor: (i) Junction law: It states that in any isolated system of capacitor the net charge is conserved. So, the incoming charge at any junction is equal to the outgoing charge from the junction. At point P the charge incoming is taken as positive and charge outgoing is taken as negative. So,
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6. Wheatstone bride combination: Calculate equivalent capacitance between points A and B. If the ratio of capacitors C1 and C2 is same to the ratio of capacitors C3 and C4 then no charge pass through capacitor C5. So, the capacitors C1, C2 and C3, C4 are in series connection and their combinations are in parallel
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Time difference during sunrise and sunset: Sun is visible to an observer after the actual sunset because of refraction of light due to denser atmosphere near the earth. The apparent shift in the direction of sun is about 0.50 leading to delay of 2 minute in actual and apparent sun set. Time taken for 3600
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Refraction through a glass slab: Let us consider a rectangular glass slab of refractive index µ and thickness t placed in air. A ray of light AB incident at B with angle of incidence i. After refraction, the ray of light bends towards the normal and goes along BC such that r is the angle
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Refraction through plane surface: Laws of refraction: 1st law – The incident ray, the refracted ray, and the normal to the interface at the point of incidence, all lie on the same plane, called the plane of incidence. 2nd law – The ratio of the sine of angle of incidence (i) to the sine of
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1. Electric potential due to uniformly charged spherical shell: Let us consider a spherical shell of radius R is charged by q. Calculate electric field at a point P, at a distance r from the centre of the shell. (i) If point P is outside the shell then potential at P is V = .
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