The electric field at distance r from an isolated point charge q is
A{'text': 'E = kq / r', 'label': 'A'}
B{'text': 'E = kq × r', 'label': 'B'}
C{'text': 'E = kq / r²', 'label': 'C'}
D{'text': 'E = kq × r²', 'label': 'D'}
Answer & Solution
Correct answer: C. {'text': 'E = kq / r²', 'label': 'C'}
1. Electric field is force per unit test charge.
2. From Coulomb's law: E = F/q_test = k q / r².
3. Direction is radially outward for positive q, inward for negative.
4. SI unit is N/C or equivalently V/m.
_Source: NCERT Class 12 Physics, Ch 1 "Electric Charges and Fields", §1.6_
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