Two parallel light rays, initially in phase and having a 500 nm wavelength, reach a detector after one of the rays passes through a 10 cm long block of glass with an index of refraction 1.5. (The situation is sketched at right, although not to scale.) The total number of wavelengths shifted between the two rays when they reach the detector is

a) 100,000
b) 200,000
c) 300,000
d) 500,000

stands for electromotive force and it is measured in volts. despite its name, it is not actually the force in the sense of being a "pushing" or "pulling" (not measured in newtons).an equation that relates emf,  ℰ,  to a battery's terminal voltage, v, current, i, and internal resistance, r, is    ℰ = v + irin this case, the emf can be interpreted as a voltage—a difference in electric potential.i would not say that it would be considered an energy. if emf can be defined as the energy/work per a unit charge from a battery or other electric source, then it is not strictly energy.

"induction" is the process of charging an object without touching it.hope my answer has you : )