Physics

posted by .

An electric current of 50 +/- 1 mA flows through an electric bulb filament that has a resistance of 10 +/- 2 ohm. Estimate the power dissipated by the filament and the associated error in the power.

  • Physics -

    The power dissipated is
    I^2*R = (.05^2)(10) = 0.025 W

    That is pretty feeble for a light bulb.

    The relative current error is negligible compared to the relative resistance error of 20%.

    The power measurement uncertainty is therefore 20% or +/- 0.005 W

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. physcial science

    Does a light bulb glow because.... a) there is burning inside b) an electric current glows c) the filament is hot d) a very small current is flowing Wouldn't you think it was because the filament was hot?
  2. Physics

    The typical resistance of the tungsten filament of a 60 watt incandescent light bulb when it is turned off is 24 ohms and its resistance when operating from a 120 volt power source is 240 ohms. Generally, an incandescent light bulb …
  3. Physics

    A 40 W (120V) light bulb has a tungsten filament of thickness 0.035 mm. The filament's operating temperature is 1500 degrees C. PART A How long is the filament?
  4. physic

    he current in a 100 watt lightbulb is 0.840 A. The filament inside the bulb is 0.140 mm in diameter. a) What is the current density in the filament?
  5. phy

    Calculate the electric power which must be supplied to the filament of of a light bulb operating at 3000K. The total surface area of the filament is 8×10−6m2 and its emissivity is 0.92.
  6. physics

    The charge per unit length on a long, straight filament is -87.0 µC/m. (a) Find the electric field 10.0 cm from the filament. Distances are measured perpendicular to the length of the filament. (Take radially inward toward the filament …
  7. physics

    The charge per unit length on a long, straight filament is -87.0 µC/m. (a) Find the electric field 10.0 cm from the filament. Distances are measured perpendicular to the length of the filament. (Take radially inward toward the filament …
  8. college physics

    The charge per unit length on a long, straight filament is -87.0 µC/m. (a) Find the electric field 10.0 cm from the filament. Distances are measured perpendicular to the length of the filament. (Take radially inward toward the filament …
  9. college physics

    The charge per unit length on a long, straight filament is -87.0 µC/m. (a) Find the electric field 10.0 cm from the filament. Distances are measured perpendicular to the length of the filament. (Take radially inward toward the filament …
  10. college physics

    The charge per unit length on a long, straight filament is -87.0 µC/m. (a) Find the electric field 10.0 cm from the filament. Distances are measured perpendicular to the length of the filament. (Take radially inward toward the filament …

More Similar Questions