A point charge `q_1` is placed inside cavity 1 and another point charge `q_2` is inside cavity 2. A point charge q is placed outside the conductor. For the situation described above, answer the following questions.
`vecE` inside the conductor at point S distant r from point charge q, due to charge on outer surface of the conductor, would be

Options

A. `q_1//4piepsilon_0r^(2)` away from the center of cavity 1
B. `q_1//4piepsilon_0r_(1)^(2)` away from the center of cavity 1
C. zero
D. `q_1//4piepsilon_0r^2` toward the center of cavity 1

Answer

D

Explanation

Electric field intensity outside the cavity to `q_(1)` and `-q_(1)` would be zero
`vec(E)_(q1)+vec(E)_(-q1)=0`
`vecE_(-q1)=-vec(E)_(q1)=(q_(1))/(4piepsilon_(0)r^(2))` toward centre of cavity 1