Question

How much work is done in moving a charge of two coulombs from a point at $118volts$ to a point at $128volts$?

• A. $10J$
• B. $20J$
• C. $\frac{1}{10}J$
• D. none of these

Answer 1

The correct option is B

$20J$

Step 1: Given

$Q=2C$

$V_1=118V$

$V_2=128V$

Step 2: Formula Used

Moving a negligible test charge between two places yields the work per unit of charge, which is stated as the difference in electric potential between those sites. Mathematically, $V=\frac{dW}{Q}or,W=Q\times dV$ where,

$dV$ is the change in the potential

$Q$ is the charge

$W$ is the work done

Step 3: Finding the work done

According to the question,

$Q=2C$ and $dV=\left(128-118\right)volts=10volts$

Substitute the known parameters in the formula $W=Q\times dV$, we get,

$$\begin{gathered} W=Q\times dV \\ \Rightarrow W=2\times 10 \\ \Rightarrow W=20J \end{gathered}$$

So, $20J$ of work is done in moving two coulombs from a point at $118volts$ to a point at $128volts$.