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Electric Charges and Fields — Physics STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 SciencePhysicsElectric Charges and Fields1 Mark
Question
For two statements are given-one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.
  1. Both A and R are true, and R is the correct explanation of A.
  2. Both A and R are true, but R is not the correct explanation of A.
  3. A is true but R is false.
  4. A is false and R is also false.
Assertion (A): Sharper is the curvature of spot on a charged body lesser will be the surface charge density at that point.
Reason (R): Electric field is non-zero inside a charged conductor.
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Answer

  1. A is false and R is also false.

Explanation:

Surface of a charged conductor is always an equipotential surface, whatever may be its shape. Hence, $\sigma\text{R}=$ constant, at every point on the surface of charged conductor i.e. at the sharpest point (R → 0) of the surface, charge density will be maximum. A uniformly charged conductor exerts no electrostatic force on a point charge located anywhere inside the conductor or electric field is zero.

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