Chapter 21, Problem 57A

To determine

Charge on a test charge.

Answer to Problem 57A

  $q=2.8\times {10}^{-5}\text{C}$ .

Explanation of Solution

Given:

Force experienced by test charge, $F=1.4\times {10}^{-8}\text{N}$

Strength of electric field $E=5\times {10}^{-4}\text{N/C}$ .

Formula Used:

As strength of an electric field is given by,

  $E=\frac{F}{q}$

Where, $E$ is electric field strength, $F$ is force experienced by charge in electric field and $q$ is the test charge.

Calculation:

So, on putting the given values in above formula,

  $\begin{array}{l}5\times {10}^{-4}=\frac{1.4\times {10}^{-8}}{q}\\ \Rightarrow q=\frac{1.4\times {10}^{-8}}{5\times {10}^{-4}}\text{C}\\ =2.8\times {10}^{-5}\text{C}\end{array}$

Conclusion:

Therefore, the charge on the test charge is $q=2.8\times {10}^{-5}\text{C}$ .