The very oddly drawn circuit above I tried consists of two f
The very oddly drawn circuit above (I tried) consists of two flashlight batteries and two Nichrome wires of different lengths and different thicknesses. The thin wire is 49cm long, and its diameter is 0.25mm. The thick wire is 15cm long, and its diameter is 0.34mm. If the emf of each flashlight battery is 1.5 volts, determine the steady state electric field inside the thin wire. Remember, you need to satisfy both the current node rule (conservation of charge) along with conservation of energy. 5.25 V/m 0 V/m 2.84 V/m 10.5 V/m
Solution
Suppose resistivity of nichrome wire is rho.
and R = rho * L / A
for thin wire:
R1 = rho * (49 cm ) / (pi * (0.25/2)^2)
R1 = k (49/0.25^2) = 784k
where k is constant.
for thick wire:
R2 = k (15 / 0.34^2) = 130k
R1 and R2 are connected in series.
and PD across (R1 + R2) = 2 x 1.5 = 3 volt
PD across thin wire = 3 x R1 / (R1 + R2)
= 2.57 Volt
and E = V/d = (2.57) / (0.49) = 5.25 V/m
