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An isolated conducting sphere of radius R carries a charge Q. The electric potential at its centre is (V(∞) = 0)
A{'text': 'kQ / (2R)', 'label': 'A'}
B{'text': 'kQ / R², directed outward', 'label': 'B'}
C{'text': 'kQ / R', 'label': 'C'}
D{'text': '0', 'label': 'D'}
Answer & Solution
Correct answer: C. {'text': 'kQ / R', 'label': 'C'}
1. By NCERT result 4 of §2.9, V is constant throughout a conductor in electrostatics.
2. The value at the centre equals the value at the surface = kQ / R.
3. (A) confuses E (=0 inside) with V; (C) is the field, not the potential.
_Source: NCERT Class 12 Physics Part I, Ch 2 §2.9 result 4_
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