A 100 W light bulb has a tungsten filament (emissivity = 0.30) which i – McqOptions

MCQOPTIONS

1.	A 100 W light bulb has a tungsten filament (emissivity = 0.30) which is required to operate at 2780 K. If the bulb is completely evacuated, calculate the minimum surface area of the tungsten filament
A.	0.98 * 10 <sup>-4</sup> m<sup>2</sup>
B.	1.98 * 10 <sup>-4</sup> m<sup>2</sup>
C.	2.98 * 10 <sup>-4</sup> m<sup>2</sup>
D.	3.98 * 10 <sup>-4</sup> m<sup>2</sup>
Answer» B. 1.98 * 10 <sup>-4</sup> m<sup>2</sup>

Discussion

No Comment Found

Related MCQs

A gray body (E = 0.8) emits the same amount of heat as a black body at 1075 K. Find out the required temperature of the gray body
For a hemisphere solid angle is measured as
The monochromatic emissivity € of a diffuse surface at 1600 K varies with wavelength in the following manner€ = 0.4 for 0 < λ < 2 = 0.8 for 2 < λ < 5Determine the total emissivity
The radiant heat transfer from a plate of 2.5 cm2 area at 1250 K to a very cold enclosure is 5.0 W. Determine the emissivity of the plate at this temperature
FOR_A_HEMISPHERE_SOLID_ANGLE_IS_MEASURED_AS?$
A_gray_body_(E_=_0.8)_emits_the_same_amount_of_heat_as_a_black_body_at_1075_K._Find_out_the_required_temperature_of_the_gray_body$
A 100 W light bulb has a tungsten filament (emissivity = 0.30) which is required to operate at 2780 K. If the bulb is completely evacuated, calculate the minimum surface area of the tungsten filament
The radiant heat transfer from a plate of 2.5 cm2 area at 1250 K to a very cold enclosure is 5.0 W. Determine the emissivity of the plate at this temperature
If a black body at 1000 K and a gray body at 1250 K emit the same amount of radiation, what should be the emissivity of the gray body?
The emissivity of the gray surface may be expressed as