Free Practice Quiz Question List

4 Magnetism Online Quiz Questions

Use this free practice quiz with 20 questions to review 4 Magnetism, test your knowledge, and prepare for your next test or exam.

20 questions

True or false

1 point

True or false: Magnetic field lines form continuous loops, and an isolated north or south magnetic pole has not been observed.

A
True
B
False

Fill in the blank

1 point

The SI unit of magnetic field $\mathbf{B}$ is the .

Choose one

1 point

On a magnetic-field diagram, the field lines are closer together in region A than in region B. What does this indicate about the field strength?

A
The field is weaker there.
B
The field is stronger there.
C
The field has no direction there.
D
The field must be uniform there.

True or false

1 point

True or false: A magnetic force can change a charged particle’s direction of motion without changing its speed or kinetic energy.

A
True
B
False

Choose one

1 point

A negatively charged particle moves through a magnetic field with velocity not parallel to the field. How should you determine its force direction using the right-hand rule?

A
In the same direction as the right-hand-rule result for a positive charge
B
Parallel to the magnetic field
C
Opposite the right-hand-rule result for a positive charge
D
Opposite the particle’s velocity

Choose all

1 point

Select all statements that correctly describe the path of a charged particle in a uniform magnetic field.

A
If velocity is entirely perpendicular to a uniform field, the path is circular.
B
If velocity is entirely parallel to a uniform field, the particle continues in a straight line.
C
If velocity has both parallel and perpendicular components, the path is helical.
D
A helical path requires the parallel component of velocity to continually change.

Written response

1 point

A charged particle moves in a uniform magnetic field with both a nonzero velocity component parallel to the field and a nonzero component perpendicular to it. What is the resulting path called?

Fill in the blank

1 point

For an ideal long solenoid, $B\approx\mu_0$ $I$ , where the blank is the number of turns per unit length.

Choose one

1 point

A long straight wire carries conventional current toward you. Viewed end-on, which way does the magnetic field circle around the wire?

A
Counterclockwise around the wire
B
Clockwise around the wire
C
Radially outward from the wire
D
Parallel to the wire

Written response

1 point

A particle has mass $4\,\text{kg}$ , speed $3\,\text{m/s}$ , charge magnitude $2\,\text{C}$ , and moves perpendicular to a uniform $2\,\text{T}$ field. Using $r=mv/(|q|B)$ , what is its circular-path radius? Enter the value in metres.

Choose all

1 point

Select all statements that correctly describe the Biot–Savart law and how it is used to find a magnetic field.

A
The current-segment vector $d\mathbf{l}$ points along the current.
B
The vector $\hat{\mathbf{r}}$ points from the current segment toward the observation point.
C
The total magnetic field is the vector sum of contributions from all current segments.
D
The total magnetic field is always just the contribution from the nearest segment.

Choose one

1 point

A current distribution has high symmetry, as with a long straight wire or an ideal solenoid. Which law is especially useful for relating the magnetic field around a closed path to the enclosed current?

A
When the particle’s charge is unknown
B
When the current distribution has high symmetry
C
Only when the field is zero outside a magnet
D
Only when currents are changing with time

Open ended

1 point

Explain how alignment of microscopic magnetic moments can make a ferromagnetic material a permanent magnet, and distinguish this mechanism from how an electromagnet produces its field.

True or false

1 point

True or false: A stationary charged particle experiences a magnetic force when it is placed in a magnetic field.

A
True
B
False

Choose one

1 point

Which change best explains why a ferromagnetic material can become strongly magnetized?

A
Its electrons stop having magnetic moments.
B
Many magnetic domains align, so their magnetic moments reinforce one another.
C
Its magnetic field lines become isolated at the north pole.
D
Its atoms gain net electric charge.

Choose one

1 point

An ideal long solenoid has a fixed number of turns per unit length. If its current is doubled, how does the magnetic field inside change?

A
The field becomes half as large.
B
The field stays the same.
C
The field becomes twice as large.
D
The field becomes four times as large.

Choose one

1 point

A negatively charged particle moves in the $+x$ direction through a magnetic field pointing in the $+y$ direction. In which direction does the magnetic force point?

A
The $+x$ direction
B
The $+y$ direction
C
The $+z$ direction
D
The $-z$ direction

Choose one

1 point

A charged particle enters a uniform magnetic field with both a nonzero velocity component parallel to the field and a nonzero component perpendicular to it. What path does it follow?

A
A straight line parallel to the field
B
A helix around the field direction
C
A circle in a plane parallel to the field
D
A path that spirals while its speed steadily increases

Written response

1 point

A magnetic force changes a charged particle's direction but does no work on it. Which energy quantity of the particle therefore remains unchanged?

Written response

1 point

A long straight wire carries a current of $8.0\,\text{A}$ . What is the magnetic field magnitude at a point $0.40\,\text{m}$ from the wire? Use $\mu_0=4\pi\times10^{-7}\,\text{T·m/A}$ .