Question

S.I unit of electric charge:
A. Coulomb
B. Ampere
C. Volt
D. Joule

Answer 1

Hint: SI unit of electric charge can be found by using the S.I units of current and time. As we know electric charge is
$q=it$
So the SI unit of electric charge can be found by dividing the S.I unit of current and time. Coulomb is the name given to unit
$C=As$
Coulomb is represented by
$C$

Complete step by step answer:
 The S.I. base units are also known as fundamental units. These include kilogram, second, Ampere, meter, Kelvin, mole, and candela. S.I units of all other physical quantities are derived from them.
We know that electric charge product of current and time. So, mathematically we can write
$q=it$
The S.I unit of time is
$s$
Current is a base S.I unit. S.I unit of current is
$A$
So, S.I. unit of electric charge will be
$A\times s=As$
 This unit is also called Coulomb
Therefore S.I the unit of electric charge is Coulomb.
Hence the correct option is A.
Note: The S.I unit of electric charge was given the name Coulomb after the scientist Charles Augustine de Coulomb in honor of his contribution to physics. He worked on theories of the force between electrical charges, as well as magnetic attraction and repulsion. Many other S.I units are also named after other scientists in honor of their contribution to physics. For example S.I unit of current ${\displaystyle \frac{kgm}{s^2}}$ is called N in honor of the great scientist Sir Isaac Newton. S.I the unit of frequency $s^{-1}$ is called Hz in honor of scientist Heinrich Hertz. Dimension of electric charge is
$$M^0{L}^{0}AT$$