|
6. How many `100`-`W` lightbulbs, connected to `120\ V` as in the figure, can be used without blowing a `15`-`A` fuse?
6. How many 100-W lightbulbs, connected to 120\ V as in the figure, can be used without blowing a 15-A fuse?  `P = IV`
`n = 18`
Given:
`P = 100\ W`
`V = 120\ V`
`I_(max) = 15\ A`
Equation:
`P = IV`
Solution:
`P = IV`
`=>`
`I = P/V`
`nI ≤ I_(max)`
`n ≤ I_(max)/I =I_(max)/(P/V) = I_(max)V/P`
`n ≤ (15\ A)(120\ V)/(100\ W)`
`n ≤ 18`
`n = 18` |