Question

Calculate the work done to bring 4c of charge from 120v to 100v

Answer 1

To calculate the work done

$w = dv \times q$
where q is charge and dv is volt , d stand for Delta(change).
$w = v2 - v1 \times q$
$w = (120 - 100) \times 4$
$w = 20 \times 4$
$w = 80$

Answer 2

Given
Initial potential difference=100v
final potential difference=120v
charge=4c
difference of potential difference=20v
w=vq
w=20×4
w=80J
we know that,
potential difference(v)=work done(w) /charge moved(q)
Here potential difference =120-100=20v
and charge moved=4c
so by putting in the formula
20=w/4
w=20×4=80J