The filament in an incandescent light bulb is a resistor that has a resistance o

Question

The filament in an incandescent light bulb is a resistor that has a resistance of 8.5 at room temperature.

Part A

By what factor does the resistance increase when a 75-W bulb connected to a 120-V power source is turned on and heats up?

15

SubmitMy AnswersGive Up

Incorrect; Try Again; 5 attempts remaining

The filament in an incandescent light bulb is a resistor that has a resistance of 8.5 at room temperature.

Part A

By what factor does the resistance increase when a 75-W bulb connected to a 120-V power source is turned on and heats up?

15

SubmitMy AnswersGive Up

Incorrect; Try Again; 5 attempts remaining

Explanation / Answer

Here ,

for the power at 120 V

P = 75 W

V = 120 V

Rhot = V^2/P

Rhot = 120^2/75

Rhot = 192 Ohm

Rhot/Rcold = 192/8.5

Rhot/Rcold = 22.6

the factor of resistance increased is 22.6

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.