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Kirchhoff's junction rule, that the sum of currents entering a junction equals the sum leaving it, is a direct consequence of
Aconservation of energy
BOhm's law for resistors
Cthe constancy of electric potential
Dconservation of charge
Answer & Solution
Correct answer: D. conservation of charge
1. In steady state there is no accumulation of charge at a junction.
2. So the rate of charge flowing in must equal the rate flowing out.
3. This is exactly conservation of charge applied to the junction.
4. The loop rule, not the junction rule, follows from energy/potential considerations (A, C).
_Source: NCERT Class 12 Physics Ch 3 "Current Electricity", p.16_
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