The displacement of a chrage `Q` in the electric field
`E = e_(1)hati + e_(2)hatj + e_(3)hatk " is " vecr = ahati + bhatj`. The work done is

Options

A. `Q(ae_(1) + be_(2))`
B. `Qsqrt((ae_(1)^(2)) + (be_(2)^(2)))`
C. `Q(e_(1) + e_(2)) sqrt(a^(2) + b^(2))`
D. `Q(sqrt (e_(1)^(2) + e_(2)^(2)))(a + b)`

Answer

A

Explanation

By using `W = Q (vecE.Deltavecr)`
`rArr W = Q[(e_(1)hati + e_(2)hatj + e_(3)hatk).(a hati + b hatj)] = Q (e_(1)a + e_(2) b)`
Since electric field is acting downwards so far balance charge must be negative.