Chapter 2, Problem 2.12P

A certain type of film resistor is available with resistance values between $10\Omega$ and $100\text{MΩ}\text{.}$ The maximum ratings for all resistors of this type are 500 V and 0.25 W. Show that the voltage rating is the controlling limit for $R>1\text{MΩ}$ and that the power rating is the controlling limit when $R<1\text{MΩ}\text{.}$