The circuit shown above consists of a single battery, whose emf is 1.4 V, and three wires made of the same material, but having different cross-sectional areas. Each thick wire has cross-sectional area 1.4e-6 m2, and is 21 cm long. The thin wire has cross-sectional area 6.4e-8 m2, and is 7.5 cm long. In this metal, the electron mobility is 6e-4 (m/s)/(V/m), and there are 8e+28 mobile electrons/m3.
Use the appropriate equation(s), plus the equation relating electron current to electric field, to solve for the factor that goes in the blank below:
EF = ______* ED
Use the appropriate equation(s) to calculate the magnitude of ED
ED = ______ V/m
Use the appropriate equation(s) to calculate the electron current at location D in the steady state:
iD = ______
E = V/L doesn't work here. How do I do this?