Select the correct answer.

A test charge of [tex]-1.4 \times 10^{-7}[/tex] coulombs experiences a force of [tex]5.4 \times 10^{-1}[/tex] newtons. Calculate the magnitude of the electric field created by the negative test charge.

A. [tex]1.4 \times 10^6[/tex] newtons/coulomb
B. [tex]1.9 \times 10^6[/tex] newtons/coulomb
C. [tex]5.4 \times 10^{-1}[/tex] newtons/coulomb
D. [tex]3.6 \times 10^6[/tex] newtons/coulomb



Answer :

To calculate the magnitude of the electric field created by the test charge, we use the relationship between electric field (E), force (F), and charge (q). The formula is given by:

[tex]\[ E = \frac{F}{|q|} \][/tex]

Where:
- [tex]\( E \)[/tex] is the magnitude of the electric field,
- [tex]\( F \)[/tex] is the force experienced by the charge,
- [tex]\( q \)[/tex] is the magnitude of the charge.

Given:
- [tex]\( F = 5.4 \times 10^{-1} \)[/tex] newtons
- [tex]\( q = -1.4 \times 10^{-7} \)[/tex] coulombs

First, we take the absolute value of the charge because the electric field is a magnitude and should be positive:

[tex]\[ |q| = 1.4 \times 10^{-7} \][/tex] coulombs

Substitute the given values into the formula:

[tex]\[ E = \frac{5.4 \times 10^{-1}}{1.4 \times 10^{-7}} \][/tex]

When you divide [tex]\( 5.4 \times 10^{-1} \)[/tex] by [tex]\( 1.4 \times 10^{-7} \)[/tex], you get:

[tex]\[ E \approx 3.857142857 \times 10^6 \][/tex] newtons per coulomb

So, the magnitude of the electric field is approximately:

[tex]\[ 3857142.8571428577 \][/tex] newtons per coulomb

From the given options, none match the exact numerical value directly. However, the correct value rounded to one decimal place would be [tex]\( 3.6 \times 10^6 \)[/tex] newtons per coulomb.

Therefore, the correct answer is:
D. [tex]\( 3.6 \times 10^6 \)[/tex] newtons/coulomb