PHY 123: Torque on a Current Loop in a Uniform Magnetic Field

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What is the magnetic dipole moment of a coil equal to?

The number of turns in the coil times the magnetic field
The unit vector normal to the loop times the magnetic field
The current in the coil times the magnetic field
The unit vector normal to the loop times the area (correct)

What is the unit of the magnetic dipole moment?

Weber per meter
Ampere per meter
Ampere square meter (correct)
Tesla square meter

What is the direction of the magnetic dipole moment of a coil?

Perpendicular to the plane of the coil (correct)
Parallel to the plane of the coil
Radial to the coil
Tangential to the coil

What is the magnitude of the magnetic dipole moment of the coil in the example?

1.72 × 10⁻³ (A⋅m²) (B) Signup and view all the answers

What is the magnetic field strength in the example?

0.35 T (A) Signup and view all the answers

What is the direction of the area vector 𝐴Ԧ in a rectangular loop?

In the direction normal to the loop (A) Signup and view all the answers

What is the force experienced by the charges moving in sides 2 and 4 of the rectangular loop?

𝐹𝐵 = 𝐵𝐼𝑎 (B) Signup and view all the answers

What is the expression for the torque 𝜏𝑚𝑎𝑥 in a rectangular loop carrying current 𝐼 in a uniform magnetic field 𝐵?

𝜏𝑚𝑎𝑥 = 𝐵𝐼𝑎𝑏 (B) Signup and view all the answers

What is the reason for the force acting only on the charges moving in sides 2 and 4 of the rectangular loop?

Because the charges are moving in a direction perpendicular to the magnetic field (B) Signup and view all the answers

What is the direction of the torque 𝜏 in a rectangular loop carrying current 𝐼 in a uniform magnetic field 𝐵?

In the direction of the cross product of the magnetic field and the area vector (D) Signup and view all the answers

What is the expression for the torque 𝜏 in a rectangular loop carrying current 𝐼 in a uniform magnetic field 𝐵?

𝜏 = 𝐼𝐴𝐵 𝑠𝑖𝑛𝜃 (B) Signup and view all the answers

What is the direction of the magnetic force FB on a positive charge according to Fleming's left-hand rule?

Thumbed out of the page (A) Signup and view all the answers

What is the magnetic dipole moment of the loop in the given situation?

6.02 × 10−4 N·m (B) Signup and view all the answers

What is the Hall voltage VH for opposite charge carriers?

Opposite in sign but same in magnitude (B) Signup and view all the answers

What is the purpose of applying another force in the opposite direction in the Hall effect?

To balance the magnetic force FB (A) Signup and view all the answers

What is the direction of the magnetic field with respect to the coil in the given situation?

Parallel to the coil (D) Signup and view all the answers

What is the expression for the magnetic force FB acting on a charge moving in a magnetic field?

FB = qv × B (C) Signup and view all the answers

What is the condition for the Hall voltage VH to become zero?

When FB equals FE (B) Signup and view all the answers

What is the relationship between the Hall voltage VH and the current I?

VH is directly proportional to I (D) Signup and view all the answers

What is the Hall coefficient RH?

1 / nq (C) Signup and view all the answers

What is the purpose of a properly calibrated conductor in the Hall effect?

To measure the magnetic field strength (C) Signup and view all the answers

What is the direction of the magnetic field with respect to the strip in the given example?

Perpendicular to the strip (D) Signup and view all the answers

What is the unit of the Hall coefficient RH?

Meter squared per coulomb (A) Signup and view all the answers

What is the physical quantity that is being measured by the Hall voltage?

Current density (D) Signup and view all the answers

What is the direction of the magnetic field in the example with respect to the copper strip?

Perpendicular to the strip (A) Signup and view all the answers

What is the relationship between the Hall voltage and the current in the strip?

The Hall voltage is directly proportional to the current (D) Signup and view all the answers

What is the unit of the molar mass of copper?

g/mol (C) Signup and view all the answers

What is the purpose of the Hall effect?

To measure the current density in a material (C) Signup and view all the answers

What is the significance of the Avogadro's number in the Hall voltage equation?

It represents the number of electrons in a mole of copper (C) Signup and view all the answers