An electron starts from rest and is accelerated through a potential difference V. The electron moves in a path perpendicular to the magnetic field B. The path of the electron makes a circle of radius R. Which of the following gives the formula for the charge to mass ratio (e/m) of the electron?

a. e/m= 2V/B^2. R^2
b. e/m= B^2R^2/2V
c. e/m= 2VB^2/R^2
d. e/m= R^2/ 2VB^2
e. e/m = 2VR^2/ B^2
f. e/m= B^2/ 2VR^2
g. e/m= 2VB^2R^2
h. None of these

Bag of bolts weight 29.4n

The answer is a.  i hope this

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.