Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
Concepts Of Physics MCQ Edition [Volume 1]
Exam
Concepts Of Physics MCQ Edition [Volume 1]
Subject
Physics
Chapter
Photometry

Concepts Of Physics MCQ Edition [Volume 1] · Physics · Photometry

Select the correct options from the following.

Select the correct options from the following.

Options

  1. ARelative luminosity is a quantity without dimensions.
  2. BRadiant flux and power possess identical dimensions.
  3. CLuminous flux and radiant flux possess identical dimensions.
  4. DLuminous flux and luminous intensity possess identical dimensions.

Correct answer

D. Luminous flux and luminous intensity possess identical dimensions.

Step-by-step solution

Relative luminosity is defined as the ratio of the luminosity of a particular wavelength to the maximum luminosity. Being a ratio of two identical quantities, it is a dimensionless quantity.

Radiant flux is the total radiant energy emitted per unit time. Its unit is Watt, which is the same as that of power. Thus, radiant flux and power have identical dimensions of [ML2T−3][M L^2 T^{-3}].

Luminous flux is measured in lumens, where 1 lumen=1 candela×1 steradian1 \text{ lumen} = 1 \text{ candela} \times 1 \text{ steradian}. Since solid angle (steradian) is a dimensionless quantity, luminous flux has the same dimensions as luminous intensity, which is [J][J].

Radiant flux has dimensions of [ML2T−3][M L^2 T^{-3}], while luminous flux has dimensions of [J][J]. Hence, they do not possess identical dimensions.
Practice Photometry on Quantrex Academy →

More from Photometry

Calculate the radiant flux of a source if it emits 45 joules of energy over a period of… Concepts Of Physics MCQ Edition [Volume 1]When exposed to a 10 W source for 12 s , a photographic plate records sufficiently… Concepts Of Physics MCQ Edition [Volume 1]Based on the relative luminosity curve shown in the figure, determine the relative… Concepts Of Physics MCQ Edition [Volume 1]Based on the relative luminosity curve shown in the figure, determine the relative… Concepts Of Physics MCQ Edition [Volume 1]Based on the relative luminosity curve shown in the figure, determine the relative… Concepts Of Physics MCQ Edition [Volume 1]The relative luminosity for a wavelength of 600 nm is 0.6 . Determine the radiant flux at… Concepts Of Physics MCQ Edition [Volume 1]Based on the relative luminosity curve shown in the figure, determine the relative… Concepts Of Physics MCQ Edition [Volume 1]A monochromatic source of 1 W produces a luminous flux of 450 lumen . Determine the… Concepts Of Physics MCQ Edition [Volume 1] Full Photometry list All Concepts Of Physics MCQ Edition [Volume 1] PYQs