21.5-21.7

Which best describes the meaning of τ in τ = NIABsinΦ ?

• torque (m)

• NET torque on a coil (N ⋅ m)

• torque on a coil (N ⋅ m)

• torque on a straight wire (N)

Which best describes the meaning of N in τ = NIABsinΦ ?

• number of spins the wire makes

• number of wires

• number of electrons in the current

• number of loops in the coil

What is RHR-2 used for?

• determining the direction of the magnetic field around a loop of current-carrying wire

• determining the direction of the magnetic field around a current-carrying wire

• determining the direction of the magnetic force around a current-carrying wire

• determining the direction of a current in a loop of current-carrying wire

When using RHR - 2, you should point your thumb in the direction of the __________________ and your fingers curl in the direction of the _________________.

• current; magnetic force

• magnetic force; current

• current; field lines

• field lines; current

What is RHR-3 used for?

• determining the direction of the magnetic field around a loop of current-carrying wire

• determining the direction of the magnetic field around a straight current-carrying wire

• determining the direction of the current in a straight current-carrying wire

• determining the direction of the magnetic force in a loop of current-carrying wire

When using RHR-3, you should curl your fingers along the direction of the ________________ and your thumb points in the direction of the ________________.

• magnetic field; magnetic force

• current; magnetic force

• current; magnetic field

• magnetic field; current

Stationary charges create ____­­_______ fields. Moving charges create _____________ fields. _______________ magnetic fields produce a _____________ current.

• Magnetic; Electric; Changing; Induced

• Electric; Electric; Static; Induced

• Electric; Magnetic; Changing; Induced

• Magnetic; Magnetic; Static; Induced

What are the definition and units of ε in: ε = vBL?

• electricity (V)

• electromagnetic force / emf (N)

• electricity (N)

• electromagnetic force / emf (V)