- ACase (i) contradicts Gauss’s law for electrostatic fields.
- BCase (ii) contradicts Gauss’s law for magnetic fields.
- CCase (i) agrees with $\oint\text{E.dl=0.}$
- DCase (ii) contradict $\oint\text{H.dl}=\text{I}_\text{en}$.
Solution:
Key concept: The electrostatic field lines, do not form a continuous closed path (this follows from the conservative nature of electric field) while the magnetic field lines form the closed paths.
According to the Gauss' law, $\oint\text{E.ds}=\frac{\text{q}}{\in_0}$ for electronstatic field. It does not contradict foe eletrostatic fields as the elecric field lines do not form a continuous closed path.
According to Gauss' law in magnetism.
$\oint\text{B.ds}=0$
Which implies that number of magnetic field lines entering the Gaussian surface is equal to the number of magnetic field lines leaving it. Therefore case (ii) is not possible.
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(b) |
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(c) |
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(a) |
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(c) |
(d) |
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(c) Zero at all points inside the loop |
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(a) 0.8 C |
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(a) Convex mirror of focal length 10 cm |
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(c) Concave mirror of focal length 60 cm |
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(a) A proton |
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