Question

The figure below shows a variable resistor in a dimmer switch.
How would you turn the switch to make the lights: $\left(a\right)$ brighter, and $\left(b\right)$ dimmer? Explain.

Answer 1

$\left(a\right)$ Turn Left $⟶$ Resistance decreases

$⟶I^{2}R/\frac{V^2}{R}$ increases (Brighter)

$\left(b\right)$ Turn Right $⟶$ Resistance increases

$⟶$ Current decreases

$⟶I^{2}R$ decreases $/\frac{V^2}{R}$ decreases (Dimmer)