Question

The wattage rating of an appliance is given as W, in watts, and varies jointly as the resistance, R, in ohms, and as the square of the current, I, in amperes. If the wattage is 90 watts when the resistance is 250 ohms and the current is 0.6 amperes, find the wattage when the resistance is 300 ohms and the current is 0.2 amperes.

A. 18,000 watts
B. 120 watts
C. 12 watts
D. 60 watts

Answer 1

12 W

Explanation:

Taking first case to establish the value of k

Substituting W with 90, I with 0.6 and R with 250 then

Now when resistance is 300 and current 0.2 then

`W= 1* 300* 0.4^(2)`