Question

four identical charges + 50 microcoulomb each are placed one at each corner of a square of Side 2 metre how much external energy is required to bring another charge of + 50 microcoulomb from infinity to the centre of the square
$a = 9 \times 10 {}^{9} nm {}^{2} \div c \:$

Answer 1

energy is required to bring another charge of +50 microcoulomb from infinity to the centre of the square , E = q∆V

where ∆V is potential difference.

potential at centre of square , V = 4kq/(r/√2)

= 4√2kq/r

here, k = 9 × 10^9 Nm²/C², q = 50 × 10^-6 C and r = 2m

so, V = 4√2 × 9 × 10^9 × 50 × 10^-6/(2)

= 2√2 × 9 × 50 × 10³

= 900√2 × 10³

= 1272.6 × 10³

= 1.272 × 10^6 volts

and potential at infinity , V' = 0

now, E = q ∆V

= +50 × 10^-6 × (1.272, × 10^6 - 0)

= 63.6J ≈ 64J

hence, energy required = 64 J

Answer 2

Answer:answer is attached

Explanation:see down