What is the potential difference between xi=10cm and xf=30cm in the uniform electric field Ex=2000V/m? Express your answer to two significant figures and include the appropriate units.

∆V= -400 Volts

Explanation:

xi= 10 cm= 0.1 m

xf= 30 cm = 0.3 m

E= 2000 V/m

We have the equation

∆V=-E (∆d)= E (xf -xi)

∆V=-2000V/m (0.3 -0.1)m

∆V= -400 Volts

current and voltage can both be different in different parts of a circuit so it matters where you place the ammeter and voltmete