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AP EAMCET202124 Aug 2021Evening ShiftPhysicsElectrostaticsActual

A unit positive charge has to be brought from infinity to a midpoint between two charges 20 C and 10 C separated by a distance of 50 ~m . How much work will be required?

Options

  1. A10.8 10^4 ~J
  2. B10.8 10^3 ~J
  3. C1.08 10^6 ~J
  4. D0.54 10^5 ~J

Correct answer

B. 10.8 10^3 ~J

Step-by-step solution

Given that, two charges q₁ and q₂ separated by d=50 ~m , q₁=20 C and q₂=10 C Work done in bringing q=1 C from infinite to point MW=q V where, V be the electric potential at M due to charges q₁ and q₂ . W=q [ K q₁ ( d 2 ) + K q₂ ( d 2 ) ]= 2 K q d [q₁+q₂ ] Substituting the values, we get aligned W & = 2 9 10^9 1 50 [20+10] 10⁻⁶ & =10.8 10^3 ~J aligned

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