Question

How much is the energy change of a charge of -20 nanocoulombs that moves in an electric field from an equipotential of +3 volts to an equipotential of +12 volts?

a) -0.4 microjoules
b) -0.8 microjoules
c) -1.2 microjoules
d) -1.6 microjoules

Answer 1

The energy change of the charge is -0.18 microjoules, which is closest to option (a) -0.4 microjoules.

Step-by-step explanation:

To calculate the energy change of a charge moving in an electric field, we can use the equation:

ΔE = qΔV

where ΔE is the energy change, q is the charge, and ΔV is the change in potential.

In this case, the charge q is -20 nanocoulombs and the change in potential ΔV is 12 volts - 3 volts = 9 volts.

Plugging in these values into the equation, we get:

ΔE = (-20 x 10^(-9)) x 9

Simplifying the expression gives us:

ΔE = -180 x 10^(-9) joules

Converting to microjoules:

ΔE = -0.18 microjoules

Therefore, the energy change of the charge is -0.18 microjoules, which is closest to option (a) -0.4 microjoules.