Help me out with this question...

Question

A straight wire of 120 cm carries directional current of 0.25A.If the space is affected by magnetic field of 0.5T that perpendicular to the current,thus the magnitude of Lorentz force of the wire is...

A.0.15N
B.0.30N
C.0.60N
D.30N
E.60N

Answer 1

This is clear. Step 1: Always draw a diagram! Follow each word with your eyes one by one. Breathe as you do this focus on the words and your breath. Awesome you're doing great.

Draw the wire going down label current I = 0.25A (I is the variable, A is amps the unit)

Then, draw the magnetic field as arrows pointing to the left (they are perpendicular, as it says, so it's either left or right). Label it as B = 0.5 T (B is the variable for magnetic field, T is Tesla, the unit)

Next, structure the information as variables and units.

What do you know?

1. I = 0.25A the current
2. L = 120 cm the length --> is this in the correct units? We need meters for all equations to work properly --> so divide by 100 to convert to meters (120 ÷ 100 = 1.2)
3. Rewrite as L = 1.2 m (m is meters)
4. B = 0.5 T the magnetic field

Isn't organizing fun and helpful!

Ask: what is the equation for the magnetic force on a wire?

F_B = I*L*B yay! We have all of these variables we just listed them!

Plug in the numbers for each variable:

FB = I*L*B = ... I'll let you do the rest!