Respuesta :
Answer:
Finally current will be
i = 0.35 A
Explanation:
As we know that power of the bulb is given by the formula
[tex]P = \frac{V^2}{R}[/tex]
now we have
[tex]P = 60 W[/tex]
R = 240 ohm
so we have
[tex]60 = \frac{V^2}{240}[/tex]
[tex]V = 120 Volts[/tex]
now the current in the bulb is given as
[tex]i = \frac{V}{R}[/tex]
[tex]i = \frac{120}{240} = 0.5 A[/tex]
now when length of the filament is double
so the resistance of the wire also gets double
so we have
[tex]P = \frac{V^2}{R}[/tex]
[tex]60 = \frac{V^2}{480}[/tex]
[tex]V = 169.7 volts[/tex]
now the current in the bulb is given as
[tex]V = i R[/tex]
[tex]169.7 = i(480)[/tex]
[tex]i = 0.35 A[/tex]
