Point charge q moves from point P to point S along the path PQRS (as shown in fig.) in a uniform electric field E pointing co-parallel to the positive direction of X-axis. The coordinates of the points P , Q , R and S are ( a , b , 0), (2 a , 0,0),( a ,- b , 0) and (0,0. 0) respectively. The workdone by the field in the above case is given by the expression

Question

Point charge q moves from point P to point S along the path PQRS (as shown in fig.) in a uniform electric field E pointing co-parallel to the positive direction of X-axis. The coordinates of the points P , Q , R and S are ( a , b , 0), (2 a , 0,0),( a ,- b , 0) and (0,0. 0) respectively. The workdone by the field in the above case is given by the expression (A) q EA (B) -q E A  (C) q EA √2 (D) q E √[(2 a)2+b2]

Tardigrade Admin · Accepted Answer

w = vec F ⋅ vec s =E q hat i ⋅(- a hat i - b hatj )=-E q a

$qE A$

$- qE A$

$qE A 2$

$qE [(2 a)^{2} + b^{2}]$

$w = F \cdot s = Eq \hat{i} \cdot (- a \hat{i} - b \hat{j}) = - Eq a$

qEA

−qEA

qEA2​

qE[(2a)2+b2]​

w=F⋅s=Eqi^⋅(−ai^−bj^​)=−Eqa

$qE A$

$- qE A$

$qE A 2$

$qE [(2 a)^{2} + b^{2}]$

$w = F \cdot s = Eq \hat{i} \cdot (- a \hat{i} - b \hat{j}) = - Eq a$