Given data:
[tex]\begin{gathered} V=12\text{ V} \\ I=0.5\text{ A} \end{gathered}[/tex]
The Ohm's law is given as,
[tex]V=IR[/tex]
Here, V is the voltage, I is the current and R is the resistance.
Rearranging the above equation, the expression for the resistance is given as,
[tex]R=\frac{V}{I}[/tex]
Substituting the known values,
[tex]\begin{gathered} R=\frac{12\text{ V}}{0.5\text{ A}} \\ =24\text{ }\Omega \end{gathered}[/tex]
Therefore, the value of resistor R is 24 Ω. Hence, option (a) is the correct choice.
