A 12 ohm hair dryer is plugged into a 240 V power supply. What is the current?

Given,
The resistance of the hairdryer, R=12 Ω
The voltage of the power supply, V=240 V
From Ohm's law,
[tex]V=IR[/tex]Where I is the current.
On substituting the known values,
[tex]\begin{gathered} 240=I\times12 \\ \Rightarrow I=\frac{240}{12} \\ =20\text{ A} \end{gathered}[/tex]Thus the current is 20 A.