Quiz: Magnetic Fields & Forces on Conductors and Charges

The equation F = B I l sin(θ) describes the force on a current-carrying conductor. What happens to the force if the angle θ is increased from 0 degrees to 90 degrees?

• The force remains constant.

• The force decreases.

• The force increases.

• The force becomes zero.

A proton moves through a magnetic field at a velocity of 2.0 × 10^5 m/s. If the magnetic field strength is 0.1 T and the angle between the velocity and the field is 90 degrees, what is the force experienced by the proton?

• 2.0 × 10^4 N

• 2.0 × 10^5 N

• 2.0 × 10^6 N

• 2.0 × 10^7 N

When a charged particle moves parallel to the magnetic field, what is the force acting on it?

• Maximum force

• Minimum force

• Zero force

• Variable force

Which of the following statements about the magnetic field around a long straight wire is true?

• The field strength increases with distance from the wire.

• The field forms concentric circles around the wire.

• The field is uniform in strength at all distances.

If the current in a wire is doubled while the distance from the wire remains constant, what happens to the magnetic field strength around the wire?

• It remains the same.

• It doubles.

• It quadruples.

• It halves.

In the equation B = μ₀ I / (2πr), what does μ₀ represent?

• Magnetic field strength

• Permeability of free space

• Current

• Distance from the wire

If a wire carrying a current of 3 A is placed in a magnetic field of 0.2 T at an angle of 30 degrees, what is the force on the wire?

• 0.3 N

• 0.6 N

• 0.9 N

• 1.2 N

Mae'r hafaliad F = B I l sin(θ) yn disgrifio'r grym ar ddargludydd sy'n cario cerrynt. Beth sy'n digwydd i'r grym os yw'r ongl θ yn cynyddu o 0 gradd i 90 gradd?

• Mae'r grym yn aros yn gyson.

• Mae'r grym yn lleihau.

• Mae'r grym yn cynyddu.

• Nid yw'r grym yn bodoli.

Pan fydd gronyn â gwefr yn symud yn baralel i'r maes magnetig, pa rym sy'n gweithredu arno?

• Grym mwyaf posibl

• Grym bychan

• Grym sero

• Grym newidiol

Yn yr hafaliad B = μ₀ I / (2πr), beth mae μ₀ yn ei gynrychioli?

• Cryfder y maes magnetig

• Athreiddedd gofod rhydd

• Cerrynt

• Pellter oddi wrth y wifren