Consider a spherical shell of radius $R$ with a total charge $+ Q$ uniformly spread on its surface (centre of the shell lies at the origin $x=0$ ). Two point charges $+q$ and $-q$ are brought, one after the other from far away and placed at $x=-a / 2$ and $x=+a / 2( < R)$, respectively. Magnitude of the work done in this process is
Consider a spherical shell of radius $R$ with a total charge $+ Q$ uniformly spread on its surface (centre of the shell lies at the origin $x=0$ ). Two point charges $+q$ and $-q$ are brought, one after the other from far away and placed at $x=-a / 2$ and $x=+a / 2( < R)$, respectively. Magnitude of the work done in this process is
- [KVPY 2014]
- A
$(Q+q)^2 / 4 \pi \varepsilon_0 \alpha$
- B
zero
- C
$q^2 / 4 \pi \varepsilon_0 a$
- D
$Q q / 4 \pi \varepsilon_0 a$
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- [IIT 2020]
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- [AIIMS 1997]