Question

${Joules}/{Coulomb}$ is the same as_____
A.Watt
B.Ampere
C.Volt
D.Ohm

Answer 1

Joules is the unit of work or energy. Coulomb is the unit of electric charge. Use the formula for work done in moving a charge q in a region having potential V.

Complete answer:
Work done in moving a charge q in a region having potential V is given by,
W=qV ...(1)
Where, W is the work done
q is the charge
V is the potential
We know, S.I. The unit of work is Joules and that of charge is Coulomb. And the S.I. The unit of potential is Volt.
So, substituting these units in the equation. (1) we get,
Joules=Coulomb × Volt
Rearranging the above expression we get,
$\dfrac{Joules}{Coulomb}=Volt$
Thus, ${Joules}/{Coulomb}$ is the same as the Volt which is a unit of electric potential.

Hence, the correct answer is option C i.e. Volt.

Additional Information:
According to Ohm's law, Volt can be expressed as Volt= Ampere × Ohms.
Volt can be defined as the electric potential along a wire, when 1 Ampere electric current dissipates the power of 1 Watt. Thus, it can also be expressed as $Volt=\dfrac {Watt}{Ampere}$.

Note:
C.G.S unit of electric charge is statcoulomb and that of work done is erg. The C.G.S unit of electric potential is statvolt. We can find the relation between C.G.S units of these quantities, using equation. (1). Thus, substituting C.G.S units in equation.(1) we get,
erg = statcoulomb × statvolt
Rearranging the above expression we get,
$\dfrac{erg}{statcoulomb}=statvolt$
Thus, ${erg}/{statcoulomb}$ is the same as the statvolt which is the C.G.S unit of electric potential.
To solve such kinds of problems, you should know at least the basic units of quantities.