Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app

Concepts Of Physics MCQ Edition [Volume 1]PhysicsPhotometry

Calculate the radiant flux of a source if it emits 45 joules of energy over a period of 15 s .

Options

A0.33 W
B675 W
C3 W
D30 W

Correct answer

C. 3 W

Step-by-step solution

Radiant flux is defined as the total radiant energy emitted per unit time. = E t Given E = 45 J and t = 15 s . = 45 15 = 3 W

Practice Photometry on Quantrex Academy →

More from Photometry

When exposed to a 10 W source for 12 s , a photographic plate records sufficiently intense lines. To obtain equally intense lines, what should be the exposure time for a 12 W sourc Based on the relative luminosity curve shown in the figure, determine the relative luminosity of wavelength 580 nm .Based on the relative luminosity curve shown in the figure, determine the relative luminosity of wavelength 520 nm .Based on the relative luminosity curve shown in the figure, determine the relative luminosity of wavelength 600 nm .The relative luminosity for a wavelength of 600 nm is 0.6 . Determine the radiant flux at 600 nm required to generate the same brightness sensation as that produced by a radiant fl Based on the relative luminosity curve shown in the figure, determine the relative luminosity of wavelength 480 nm .A monochromatic source of 1 W produces a luminous flux of 450 lumen . Determine the relative luminosity at the emitted wavelength.A source emits light of wavelengths 555 nm and 600 nm . The radiant flux of the 555 nm part is 40 W while that of the 600 nm part is 30 W . The relative luminosity at 600 nm is 0.6 Full Photometry list All Concepts Of Physics MCQ Edition [Volume 1] PYQs