Question

A point charge Q is placed in uniform electric field Ē=Ei+Ej at position (a.
b). Find work done in moving it to position (c. d):​

Answer 1

Answer:

Iron surface is coated with paint. ... The iron surface is shielded from oxygen and moisture. b) Iron is coated with another metal such as zinc. The process is called galvanising.

Answer 2

Answer:

The work done in moving a charge from position (a. b) to (c. d) is $\big[-Q\big(E(c-a)+E(d-b)\big)\big]~J$

Explanation:

Given a point charge Q is placed in uniform electric field $\vec E=E\hat i+E\hat j$

Charge is moved from position (a. b) to position (c. d)

Work done in moving a charge from one point to the another is given by

$W_{A\rightarrow B} =-Q\int\limits^{B}_{A} {\vec E.d\vec r}$

Then work done in moving a charge from (a. b) to  (c. d) is

$W=-Q\int\limits^{c,d}_{a,b} {(E\hat i+E\hat j).(dx\hat i+dy\hat j)}$

$=-Q\int\limits^{c,d}_{a,b} {(Edx+Edy)$

$=-Q(Ex+Ey)\Big|\limits^{c,d}_{a,b}$

$=-Q\big(E(c-a)+E(d-b)\big)$

Therefore, the work done in moving a charge from position (a. b) to position (c. d) is $\big[-Q\big(E(c-a)+E(d-b)\big)\big]~J$