Question

Two point charges A and B 5 and 6 microcoulomb are kept 12cm apart in air .calculate work done when the charge B is move by 2 cm towards charge A

Answer 1

Answer:

0.45 J

Explanation:

Given in the question that there are two charges A and B

Value of first charge = +5 uC

Value of second charge = +6 uC

Distance between them = 12 cm

Distance after the charge B have move 2 cm toward charge A = 12-2 = 10cm

Work done in moving the charge is equal to the gain in the electrostatic potential of the system U

U1 = $\frac{1}{4\pi e }\frac{q1q2}{r1}$

U2 = $\frac{1}{4\pi e }\frac{q1q2}{r2}$

WD = U2 - U1

$WD=\frac{q1q2}{4\pi e}(\frac{1}{r2}-\frac{1}{r1})$

Plug in the values

$\frac{(5*10^-6)(6*10^-6)}{4\pi e}(\frac{1}{10*10^-2}-\frac{1}{12*10^-2})$

= 0.45 J