Which of the following expressions gives the flux Φ through a flat surface of area A due to a constant magnetic field of magnitude B which makes an angle θ with the chosen perpendicular to the surface? A :

Φ = B cos θ / A

B :

Φ = A B sin θ

C :

Φ = A B

D :

Φ = A B cos θ

Suppose that a comet that was seen in 563 a. d. by chinese astronomers was spotted again in year 1951. assume the time between observations is the period of the comet and take its eccentricity as 0.986. what are (a) the semimajor axis of the comet's orbit and (b) its greatest distance from the sun?

Glass is transparent to visibile light under normal conditions; however, at extremely high intensities, glass will absorb most of the light incident upon it. this works through a process known as multiphoton absorption. in this process, several photons are absorbed at the same time. if very intense light whose photons carry 2ev of energy is shined onto a material with a band gap of 4ev, that light can be absorbed through two-photon absorption, because two photons have the right amount of energy to bridge the band gap. what is the minimum number of photons of 800-nm light that are needed to equal or exceed the band gap of fused silica glass

What are similarities and differences between refraction, reflection, diffraction and absorption?