Question 1

A charged particle moves with velocity $$\vec{v}$$ perpendicular to a uniform magnetic field $$\vec{B}. $$What is the direction of the force acting on the particle?

Accepted Answer

Perpendicular to both $$\vec{v}$$ and $$\vec{B}$$

Question 2

Which equation correctly represents the magnetic force on a moving charge in a magnetic field?

Accepted Answer

$$F = qv 	imes B$$

Question 3

A wire of length $$L$$ carries a current $$I$$ and is placed in a magnetic field $$\vec{B}$$ perpendicular to the wire. What is the magnitude of the force on the wire?

Accepted Answer

$$F = ILB$$

Question 4

If a charged particle moves in a circle in a uniform magnetic field, what is the direction of the force acting on it at any instant?

Accepted Answer

Radially inward (toward the center)

Question 5

What is the formula for magnetic flux $$\Phi$$ through a surface of area $$A$$ when the magnetic field $$B is $$perpendicular to the surface?

Accepted Answer

$$\Phi = BA$$

Question 6

According to Gauss's Law for magnetism, what is the net magnetic flux through any closed surface?

Accepted Answer

Always zero

Question 7

A positive test charge is placed in a region with both electric field $$\vec{E}$$ and magnetic field $$\vec{B}. $$What is the total force acting on the charge?

Accepted Answer

$$F = q[E + v 	imes B]$$

Question 8

If the velocity of a charged particle is parallel to the magnetic field, what is the magnetic force acting on it?

Accepted Answer

Zero

Question 9

Which of the following best describes the right-hand rule for determining the direction of the force on a positive charge moving in a magnetic field?

Accepted Answer

Thumb points in the direction of $$\vec{v}$$, fingers in the direction of $$\vec{B}$$, palm shows force

Question 10

A wire carrying current $$I is $$bent into a circular loop of radius $$r$$ and placed in a uniform magnetic field $$B$$ perpendicular to the plane of the loop. What is the net force on the loop?

Accepted Answer

$$F = 0$$

Question 11

A proton and an electron enter a uniform magnetic field with the same velocity perpendicular to the field. How do their paths differ?

Accepted Answer

They move in circles in opposite directions

Question 12

If the area vector $$\vec{A} is $$not perpendicular to the magnetic field $$\vec{B}$$, what is the expression for the magnetic flux $$\Phi$$?

Accepted Answer

$$\Phi = B \cos \phi \cdot A$$

Question 13

Which statement about Gauss's Law for magnetism is correct?

Accepted Answer

It states that the net magnetic flux through any closed surface is zero

Question 14

A straight wire of length $$L$$ carrying current $$I is $$placed at an angle $$\phi to a $$uniform magnetic field $$B. $$What is the expression for the force on the wire?

Accepted Answer

$$F = ILB \sin \phi$$

Question 15

What is the effect of increasing the speed of a charged particle moving perpendicular to a magnetic field?

Accepted Answer

The force increases

Question 16

Which of the following is true about the force on a current-carrying wire in a magnetic field?

Accepted Answer

The force is perpendicular to both the wire and the magnetic field

Question 17

If a wire is not straight, how is the force on the wire in a magnetic field calculated?

Accepted Answer

$$dF = IdL 	imes B$$

Question 18

A test charge is used to measure the magnetic field $$B at a $$point. What must be true about the test charge?

Accepted Answer

It must be extremely small

Question 19

Which equation is used to calculate the magnetic flux $$\Phi_B$$ through a non-uniform surface?

Accepted Answer

$$\Phi_B = \int B \cos \phi \, dA$$

Chapter 27 Part III - Magnetic Forces, Magnetic Flux, and Gauss’s Law for Magnetism

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