Electromagnetism
B) Move the loop parallel to a magnetic field.
All of the following are ways to induce a voltage in a loop of wire except which one? A) Insert the loop into a changing magnetic field. B) Move the loop parallel to a magnetic field. C) Rotate the loop in a magnetic field. D) Move the loop into or out of a magnetic field.
A) Magnetic field lines appear to end at the north pole of a magnet.
All of the following statements about magnetic field lines around a permanent magnet are true except which one? A) Magnetic field lines appear to end at the north pole of a magnet. B) Magnetic field lines have no beginning or end. C) Magnetic field lines always form a closed loop. D) In a permanent magnet, the field lines actually continue within the magnet itself.
0.076 N
A 0.050-m-long wire is carrying a current of 2.0 A at right angles to a 0.76-T magnetic field. What is the magnitude of the force exerted by the magnetic field on the wire?
magnetic field
A current can be induced in a closed circuit without the use of a battery or an electrical power supply by moving the circuit through a
form circles that go around the wire
A current in a long, straight wire produces a magnetic field. These magnetic field lines
0.74 T
A current-carrying wire 45 cm long is positioned perpendicular to a uniform magnetic field. If the current is 12.0 A and there is a resultant force of 4.0 N on the wire due to the interaction of the current and field, what is the magnetic field strength?
south to north
A long, straight, current-carrying wire runs from north to south. A compass needle placed underneath the wire points with its N-pole toward the west. In what direction is the current flowing through the wire?
domain; no
A microscopic magnetic region composed of a group of atoms whose magnetic fields are aligned in a common direction is called a(n) ____. In most materials, when these groups are randomly distributed, the substance will show ____ magnetism.
south; repelled
A solenoid is in an upright position on a table. A counterclockwise current of electrons—when viewed from above—causes the solenoid to have a ____ magnetic pole at its bottom end. If a compass is placed at the top of the solenoid, the north pole of the compass would be ____.
3227 V
A step-up transformer used on a 120 V line has 95 turns on the primary and 2555 turns on the secondary. What is the voltage across the secondary?
3.79 A
How much current is required to produce a force of 0.85 N on a 35 cm long wire oriented at right angles to a 0.64 T magnetic field?
line up in mainly one direction
In a magnetized substance, the domains
run the wire parallel to the magnetic field
In which direction, in relation to a magnetic field, would you run a current-carrying wire so that the force on it, resulting from the field, is minimized or even made to be zero?
6.0 A
Two loops of wire are arranged so that a changing current in the primary will induce a current in the secondary. The secondary loop has half as many turns as the primary loop. As long as the current in the primary is steady at 3.0 A alternating current, the current in the secondary will be
D) all of the above
Under which of the following conditions is the net magnetic force on a charged particle equal to zero? A) when the particle is stationary B) when the particle is moving parallel to the magnetic field C) when the particle is not charged D) all of the above
it is at right angles to both the direction of the magnetic field and the direction of the current
What is the direction of the force acting on a current-carrying conductor lying in a magnetic field?
the magnitude is greatest close to the poles
Where is the magnitude of the magnetic field around a permanent magnet greatest?
A) mechanical energy to electrical energy
Which conversion process is the basic function of the electric generator? A) mechanical energy to electrical energy B) electrical energy to mechanical energy C) low emf to high emf, or vice versa D) alternating current to direct current
A) 1 N/(A⋅m)
Which of the following expressions shows the correct relationship between 1 T (1 tesla) and other common units? A) 1 N/(A⋅m) B) 1 N⋅m/A C) 1 N⋅A⋅m D) 1 A/(N⋅m)
D) all of the above
Which of the following options can be used to generate electricity? A) Move the circuit loop into and out of a magnetic field. B) Change the magnetic field strength around the circuit loop. C) Change the orientation of the circuit loop with respect to the magnetic field. D) all of the above
B) Unlike poles repel each other.
Which of the following situations is not true for magnets? A) Like poles repel each other. B) Unlike poles repel each other. C) North poles repel each other. D) A north pole and a south pole will attract each other.
B) The geographic South Pole of Earth and Earth's magnetic north pole are relatively close to each other.
Which of the following statements about Earth's magnetic field is true? A) The geographic North Pole of Earth and Earth's magnetic north pole are at the same location. B) The geographic South Pole of Earth and Earth's magnetic north pole are relatively close to each other. C) The north needle of a compass always points to the geographic North Pole of Earth. D) The north needle of a compass points to Earth's magnetic north pole.
