Which of the following shows a black body's energy density?

Explanation

Option A : The equation E=hcv shows the relationship between energy (E), Planck's constant (h), the speed of light (c), and the frequency (v) of electromagnetic radiation. Specifically, it states that the energy of a photon of electromagnetic radiation is equal to its frequency multiplied by Planck's constant. This equation is fundamental to the field of quantum mechanics and is used to describe the behaviour of light and other forms of electromagnetic radiation. Option B : The equation E=c/v shows the relationship between the energy (E), speed of light (c), and wavelength (λ) of electromagnetic radiation. Specifically, it states that the energy of a photon of electromagnetic radiation is equal to its frequency multiplied by Planck's constant. This equation is fundamental to the field of quantum mechanics and is used to describe the behaviour of light and other forms of electromagnetic radiation. Option C : The equation E=CV shows the relationship between the energy stored in a capacitor (E), the capacitance of the capacitor (C), and the voltage across the capacitor (V). Specifically, it states that the energy stored in a capacitor is equal to one-half of the product of its capacitance and the square of the voltage across it. This equation is important in the study of electrical circuits and is used to calculate the amount of energy stored in a capacitor at a given voltage. Option : D The energy density of a black body between λ and λ + dλ is the energy E=hc/λ of mode times the density of states for photons, times the probability that the mode is occupied. This is Planck's famous formula for the energy density of a black body.