A small bulb is rated at 7.50 W when operated at 125 V. The tungsten filament has a temperature coefficient of resistivity a = 4.50 × 10^-3 / °C. When the filament is hot and glowing, its temperature is seven times room temperature (20 °C). What is the resistance of the filament (in ohms) at room temperature?
a. 234
b. 1 350
c. 2 080
d. 4 530
e. 5 630
A
You might also like to view...
How many molecules are in:
(a) 1.0 cm3 of AIR at STP? (b) 1.0 cm3 of HELIUM at STP?
Fissioning carbon would occur with
A) absorption of energy. B) release of energy. C) neither of these
If ? 1 = 4.0 V, ? 2 = 12.0 V, R1 = 4 ?, R2 = 12 ?, C = 3 ?F, Q = 18 ?C, and I = 2.5 A, what is the potential difference Va ? Vb?
a.
?30 V
b.
30 V
c.
5.0 V
d.
?5.0 V
e.
?1.0 V
Suppose that a particle is trapped in a box. How does the spacing in energy between adjacent energy levels change as the quantum number identifying a level increases?
A) The spacing decreases. B) The spacing alternately increases and decreases, depending on whether the wave function is a sine or a cosine function. C) The spacing remains constant. D) The spacing increases.