Respuesta :
Explanation:
In Europe the standard voltage in homes is 220 V instead of the 120 V used in the United States.
100-W European bulb would be intended for use with a 220-V potential difference.
(a) If V = 220 V and P = 100 W
Power :
[tex]P=\dfrac{V^2}{R}\\\\R=\dfrac{V^2}{P}\\\\R=\dfrac{(220)^2}{100}\\\\R=484\ \Omega[/tex]
If you bring a "100-W" European bulb home to the untied States, what should be its US power rating. So,
[tex]P=\dfrac{V^2}{R}\\\\P=\dfrac{(120)^2}{484}\\\\P=29.75\ W[/tex]
or
P = 29.8 watts
(b) Let I is the current will the 100-W European bulb draw in normal use in the United States. So,
[tex]I=\dfrac{V}{R}\\\\I=\dfrac{120}{484}\\\\I=0.248\ A[/tex]
Hence, this is the required solution.
Answer:
Explanation:
Voltage in Europe, V = 220 V
Power, P = 100 W
Let R be the resistance of the bulb.
[tex]R = \frac{V^{2}}{P}[/tex]
[tex]R = \frac{220^{2}}{100}[/tex]
R = 484 ohm
(a)
Voltage in United States , V = 120 V
R = 484 ohm
Let the power is P'
[tex]P = \frac{V^{2}}{R}[/tex]
[tex]P' = \frac{120^{2}}{484}[/tex]
P' = 29.8 Watt
(b)
Let the current is i.
P' = V x i
29.8 = 120 x i
i = 0.248 A
