Assertion (A): Electric field is always zero in a cavity inside a conductor.
Reason (R): All points in a cavity inside a conductor are always at same potential.
1. Both (A) & (R) are true and the (R) is the correct explanation of the (A)
2. Both (A) & (R) are true but the (R) is not the correct explanation of the (A)
3. (A) is true but (R) is false
4. Both (A) and (R) are false
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Assertion (A) is true for an uncharged cavity in electrostatic equilibrium (electrostatic shielding). Reason (R) is also true, as \(\vec{E} = -\nabla V\), so zero field implies constant potential. However, constant potential is a consequence of zero field, not its explanation.
Assertion (A): We cannot produce electric field in a neutral conductor.
Reason (R): Neutral conductor cannot produce electric field.
1. Both (A) & (R) are true and the (R) is the correct explanation of the (A)
2. Both (A) & (R) are true but the (R) is not the correct explanation of the (A)
3. (A) is true but (R) is false
4. Both (A) and (R) are false
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In electrostatic equilibrium, the electric field inside a conductor is zero due to charge redistribution. A neutral conductor has no net charge, so it cannot be a source of electric field. Both assertion (A) and reason (R) are true, but (R) does not correctly explain (A); the zero field inside is due to charge mobility and redistribution, not simply its neutrality.
Assertion (A): A moving charge particle may gets energy from electric field.
Reason (R): Electric field works on moving charge.
1. (1) Both (A) & (R) are true and the (R) is the correct explanation of the (A)
2. (2) Both (A) & (R) are true but the (R) is not the correct explanation of the (A)
3. (3) (A) is true but (R) is false
4. (4) Both (A) and (R) are false
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An electric field exerts a force \( \vec{F} = q\vec{E} \) on a charge `\( q \)`. If the charge moves, work \( W = \int \vec{F} \cdot d\vec{l} \) can be done, changing its energy. Hence, both are true and (R) explains (A).
Assertion (A): Electric field intensity at surface of a uniformly charged spherical shell is `\( E \)`. If shell is punctured at a point then intensity at punctured point becomes `\( E/2 \)`.
Reason (R): Electric field intensity due to a spherical charge distribution can be found out by using Gauss law.
1. (1) Both (A) & (R) are true and the (R) is the correct explanation of the (A)
2. (2) Both (A) & (R) are true but the (R) is not the correct explanation of the (A)
3. (3) (A) is true but (R) is false
4. (4) Both (A) and (R) are false
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The field at a puncture is `\( E/2 \)` due to superposition. Gauss's law helps find the field for symmetric distributions, but it doesn't explain the `\( E/2 \)` effect at the puncture directly. Both (A) and (R) are true, but (R) is not the correct explanation of (A).
Assertion (A): A point charge is brought in an electric field. The field at a nearby point will increases, whatever be the nature of charge.
Reason (R): The direction of electric field lines is independent of the nature of charge.
1. Both (A) & (R) are true and the (R) is the correct explanation of the (A)
2. Both (A) & (R) are true but the (R) is not the correct explanation of the (A)
3. (A) is true but (R) is false
4. Both (A) and (R) are false
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Both (A) and (R) are false. The resultant electric field can increase, decrease or cancel depending on vector sum. Field line direction depends on charge sign.
Assertion (A): At a point in space, the electric field points toward east. In the region, surrounding this point the potential will be constant along north and south.
Reason (R): Electric field at a point in space is proportional to rate of change of potential with distance.
1. Both (A) & (R) are true and the (R) is the correct explanation of the (A)
2. Both (A) & (R) are true but the (R) is not the correct explanation of the (A)
3. (A) is true but (R) is false
4. Both (A) and (R) are false
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Assertion (A) is true because equipotential surfaces are perpendicular to electric field lines. Reason (R) is true as \(E = -\frac{dV}{dr}\). However, (R) describes the relation, but not why potential is constant along north-south specifically for an eastward field.