A point charge of [tex]$5.0 \times 10^{-7} \, C$[/tex] moves to the right at [tex]2.6 \times 10^5 \, \text{m/s}[/tex] in a magnetic field that is directed into the screen and has a field strength of [tex]1.8 \times 10^{-2} \, T[/tex]. What is the magnitude of the magnetic force acting on the charge?

A. 0 N
B. [tex]2.3 \times 10^{-3} \, N[/tex]
C. 23 N
D. [tex]2.3 \times 10^{11} \, N[/tex]



Answer :

To solve this problem, we need to calculate the magnitude of the magnetic force acting on a moving point charge. The relevant formula to use here is [tex]\( F = qvB \)[/tex], where:

- [tex]\( F \)[/tex] is the magnetic force,
- [tex]\( q \)[/tex] is the charge,
- [tex]\( v \)[/tex] is the velocity of the charge, and
- [tex]\( B \)[/tex] is the magnetic field strength.

We are given:
- [tex]\( q = 5.0 \times 10^{-7} \)[/tex] Coulombs,
- [tex]\( v = 2.6 \times 10^5 \)[/tex] meters per second,
- [tex]\( B = 1.8 \times 10^{-2} \)[/tex] Teslas.

Step-by-step, we substitute these values into the formula:

1. Write down the formula:
[tex]\[ F = qvB \][/tex]

2. Substitute the given values:
[tex]\[ F = (5.0 \times 10^{-7} \, \text{C}) \times (2.6 \times 10^5 \, \text{m/s}) \times (1.8 \times 10^{-2} \, \text{T}) \][/tex]

3. Calculate the product of the values:
[tex]\[ F = 5.0 \times 2.6 \times 1.8 \times 10^{-7+5-2} \, \text{N} \][/tex]

4. Simplify the power of ten:
[tex]\[ F = 5.0 \times 2.6 \times 1.8 \times 10^{-4} \, \text{N} \][/tex]

5. Multiply the constants:
[tex]\[ 5.0 \times 2.6 = 13.0 \][/tex]
[tex]\[ 13.0 \times 1.8 = 23.4 \][/tex]

6. Combine the constant with the power of ten:
[tex]\[ F = 23.4 \times 10^{-4} \, \text{N} \][/tex]

7. Convert to scientific notation:
[tex]\[ F = 2.34 \times 10^{-3} \, \text{N} \][/tex]

Therefore, the magnitude of the magnetic force acting on the charge is:

[tex]\[ F = 2.34 \times 10^{-3} \, \text{N} \][/tex]

Out of the provided answer choices:
- 0 N
- [tex]\(2.3 \times 10^{-3}\)[/tex] N (approx)
- 23 N
- [tex]\(2.3 \times 10^{11}\)[/tex] N

The closest option to [tex]\(2.34 \times 10^{-3}\)[/tex] N is [tex]\( 2.3 \times 10^{-3} \)[/tex] N.

Hence, the correct answer is:
[tex]\[ 2.3 \times 10^{-3} \, \text{N} \][/tex]