Physics Quiz

What is the expression for the charge in a section of length dl of a current-carrying wire?

• dq = I/A

• dq = nqAdl

• dq = nqAv

• dq = Idl/B

What is the correct expression for the force on a section of length dl of a current-carrying wire in a magnetic field?

• dF = nqAdl v x B

• dF = I dl x B

• dF = nqAv dl x B

• dF = I/A dl x B

For a straight segment of length L in a uniform magnetic field, what is the formula for force?

• F = nqAv L x B

• F = I/A L x B

• F = IL x B

• F = nqAdl L x B

What is the net force on a square loop of current when it is placed in a uniform magnetic field that points out of the screen?

• The net force is not zero.

• The net force depends on the current in the loop.

• The net force is zero.

• The net force depends on the side length of the square loop.

According to the examples provided, what happens to the net force on a square loop of current when the magnetic field is uniform and the loop is positioned with sides perpendicular or parallel to the field?

• The net force causes the loop to rotate.

• The net force is maximum when sides are perpendicular to the field.

• The net force is zero.

• The net force is only zero when sides are parallel to the field.

What is the net force on a closed loop of current in a uniform magnetic field B?

• It depends on the shape of the loop.

• It is always non-zero.

• It is always zero.

• It is directly proportional to the current I.

What is the relationship between the force F on a side of a square loop of current and the magnetic field B?

• F = ILB

• F = I/B

• F = B/IL

• F = I + LB

What is the expression for the torque τ on a square loop of current in a uniform magnetic field?

• τ = FL

• τ = F + L

• τ = F/L

• τ = IL^2B

What is the net torque about the center of a square loop of current when the loop is in the xy plane and B is parallel to the xz plane?

• τ = I(L/2)Bsinθ

• τ = ILBsinθ

• τ = IL^2Bsinθ

• τ = 2ILBsinθ

Which of the following statements correctly describes the forces on the near and far sides of a square loop of current in the xy plane with B parallel to the xz plane?

• Near side: out of the screen, Far side: into the screen

• Near side: into the screen, Far side: out of the screen

• Both near and far sides: into the screen

• Both near and far sides: out of the screen