Question

a unit positive charge has to be brought from infinity to the mid point between the two charges 20 micro coulomb and 10 micro coulomb separated by a distance of 50m how much work will be required?

Answer 1

Answer: 10800 joules

Explanation:

Answer 2

Answer:

The work done is $10.8\times10^{3}\ J$.

Explanation:

Given that,

First charge = 20μ C

Second charge = 10μ C

Distance = 50 m

The work done by the two charges 20μC and 10​μC to bring the unit positive charge in mid point of the line joining them  will be stored as the electrical potential energy of the system.

We need to calculate the work done

Using formula of work done

$W= eV$....(I)

We need to calculate the potential

$V=V_{1}+V_{2}$

$V=\dfrac{kq_{1}}{r}+\dfrac{kq_{2}}{r}$

$V=\dfrac{k}{r}(q_{1}+q_{2})$

Put the value into the formula

$V=\dfrac{9\times10^{9}}{25}(20\times10^{-6}+10\times10^{-6})$

$V=10800\ Volt$

Now, put the value of V and e in equation (I)

$W=1\times10800\ J$

$W=10800\ J$

$W=10.8\times10^{3}\ J$

Hence, The work done is $10.8\times10^{3}\ J$.