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Find the amount of work done in rotating an electric dipole of dipole moment 3.2 x 10- 8Cm from its position of stable equilibrium to the position of unstable equilibriu - Physics

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प्रश्न

Find the amount of work done in rotating an electric dipole of dipole moment 3.2 x 10- 8Cm from its position of stable equilibrium to the position of unstable equilibrium in a uniform electric field if intensity 104 N/C.  

योग
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उत्तर

Given: p = 3.2 x 10- 8Cm, E = 104 N/C 

To Find: Work done in rotating dipole (W)

Formula: W = pE (cos θ0 - cos θ) 

Calculation: 

At stable equilibrium, θ0 = 0° 

At unstable equilibrium, θ = 180° 

From formula,

W = pE (cos θ0 - cos θ) 

= 3.2 × 10-8 × 104 (cos 0 - cos 180)

= 3.2 × 10-4 [1 - (-1)] 

= 6.4 × 10-4 J

Work done in rotating an electric dipole is 6.4 × 10-4 J.

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अध्याय 8: Electrostatics - Short Answer II

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संबंधित प्रश्न

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(Hint: The earth has an electric field of about 100 Vm−1 at its surface in the downward direction, corresponding to a surface charge density = −10−9 C m−2. Due to the slight conductivity of the atmosphere up to about 50 km (beyond which it is good conductor), about + 1800 C is pumped every second into the earth as a whole. The earth, however, does not get discharged since thunderstorms and lightning occurring continually all over the globe pump an equal amount of negative charge on the earth.)


Draw equipotential surfaces:

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(3) Can electric field exist tangential to an equipotential surface? Give reason


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Statement - 1: For practical purpose, the earth is used as a reference at zero potential in electrical circuits.

Statement - 2: The electrical potential of a sphere of radius R with charge Q uniformly distributed on the surface is given by `Q/(4piepsilon_0R)`.


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(i)
(ii)
(iii)
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