The temperature of a black body is 500 and its radiation is of wavelength 600 . If the number of oscillators with energy is 100 , 000, calculate the number of oscillators in the black body with energy 1 . (Accoding to Max. Planck, the number of oscillators with energy ℎ at a particular frequency is given by = = − ( ⁄ ) = − ( ⁄ ) (10 Marks) (b) Calculate the peak wavelength of a black body's radiation if the black body is at a temperature of 20 , 000 . (5 Marks)

An isotope undergoes radioactive decay by emitting radiation that has a –1 charge. what other characteristic does the radiation have?

Antireflective coatings on solar cells are often made by applying a thin film of silicon nitride (sinx), which has an index of refractive of 1.2, on the top of the silicon solar cell, which has a refractive index of about 3.5. however, the sun emits radiation of various wavelengths which the solar cell absorbs, and the antireflective coating can only absolutely minimize the reflection of one of these wavelengths. the coating thickness is chosen to reduce the reflection of green/yellow light (e = 2.2 ev), which is the most intense color in the solar spectrum (shown below). which of the following coatings would minimize reflection of green/yellow light? the answer is 820 nm how? what is the angular width of the central maximum of an electron traveling at 2 x 108 m/s going through a single slit of width 1 mm.

Where do magnetic lines of force enter earth?