Help I'm desperate and need help ASAP I will give brainliest to whoever gets it correct. Select the best answer from the choices below. Standing waves are formed by:

a
A wave hitting the surface of an object and bouncing back
b
Light moving from one medium to another
c
Two or more identical waves moving in opposite directions
d
Waves moving around an obstacle

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.

A). redi wish i´ve