Question

Which is bigger –a coulomb or a charge on each electron? How many electronic charges form one coulomb of charge?

Answer 1

Since in this type of question we have to know that coulomb is already a unit of charge and for finding charge we have to apply the relation between charge and number of electrons and electrons. This relation is also used to find the number of charges as asked in the second part of the question.

Complete step-by-step solution: -
Here in this given question we have to check which is greater either a coulomb or charge on 1 electron.
So first we will calculate the charge on an electron or charge of 1 electron.
This charge on 1 electron is calculated by the relation given below,
$q=ne$
where,
q is representing charge.
n is representing the number of electrons.
e is representing the electronic charge whose value is fixed.
The value of e is given as$e=1.6\times {{10}^{-19}}C$.
Here in the question only 1 electron is given
So,$n=1$.
Now charge on an electron is calculated as,

& q=1\times 1.6\times {{10}^{-19}} \\\ & q=1.6\times {{10}^{-19}}C \\\ \end{aligned}$$. This is the value of charge on 1 electron. Since this value is less than 1 Coulomb So 1 Coulomb charge is more as compared to charge on an electron. Now we have to find how many electric charges make 1 coulomb. So here we again use the same relation, $$q=ne$$ where, q is representing charge. n is representing the number of electrons. e is representing the electronic charge whose value is fixed. The value of e is given as$$e=1.6\times {{10}^{-19}}C$$. Here charge q is given, $$\begin{aligned} & q=1C \\\ & n=? \\\ \end{aligned}$$. So we again apply the same relation, $$\begin{aligned} & q=ne \\\ & \Rightarrow 1=n\times 1.6\times {{10}^{-19}} \\\ & \Rightarrow n=\dfrac{1}{1.6\times {{10}^{-19}}} \\\ & \therefore n=6.25\times {{10}^{18}}electrons \\\ \end{aligned}$$ So here we can define that 1 Coulomb is that amount of charge which can be obtained by contributing $$6.25\times {{10}^{18}}.$$electrons. So at last we can conclude that in first part of the question a coulomb has more charge than the charge on an electron and in second part this quantity of electrons$$6.25\times {{10}^{18}}.$$is required to make up 1 coulomb of charge. **Note:** Charge is an intrinsic property of any material that always exerts force on other particles placed near it .This force can be attractive or repulsive depending upon the nature of charges. Charge can never exist without mass but mass can exist without charge. Presence of charge itself is proof of material having mass.