Please answer this entire question and accurately I really need the help 3. -15
ID: 777474 • Letter: P
Question
Please answer this entire question and accurately I really need the help
3. -15 points My Notes Ask Your Teacher An incandescent light bulb is rated at 150 W when the applied voltage is 120 V (a) What is the resistance of the bulb when it is operating? (b) A hot tungsten filament in a bulb has a temperature of about 2520°C. Find the ratio of resistances when the filament is hot to when it is cold, a temperature of 20°C. Information about tungsten is in your text. (c) What is the resistance of your bulb when it is cold? switched on.) . (d) When is the current through the bulb larger? (This helps explain why bulbs burn out when When it is cold When it is hot Same current always (e) The diameter of the wire in a filament is about 0.09 mm. How long is the filament in your bulb? There is a lot of wire to fit inside a lightbulb. The filament is a coil of a coil. To see photos and read more, check INVSEE or wikipedia. Be sure to look for a microscopic image of the filament!Explanation / Answer
(a)
P=V^2/R
R=V^2/P=120*120/150=96 ohm
(b)
R/T = k
T1=2520-273=2793
T2=20-273=293
R1/T1=96/2793=0.0344
R2=KT2
=0.0344*293
10.07
R1/R2=9.6
(C)
R2=10.07
(D)
when its is cold
(E)
R = L / r²
=56e-9
r=0.09 mm
For R1=96
L=R*r² /
=4.6*107 meter
For R2=10.07
L=R*r² /
=4.5*106 meter