Physics 2 Test 2

Which of the following statements are true? When an electric field is applied to a conductor, the free electrons move only in the direction opposite the applied electric field. In a circuit, current is delivered by the positive terminal of a battery, and it is used up by the time it returns to the negative terminal of the battery. Current is the total amount of charge that passes through a conductor's full cross section at any point per unit of time. By convention, the direction of a current is taken to be the direction of flow for negative charges. In order to maintain a steady flow of current in a conductor, a steady force must be maintained on the mobile charges.

If the voltage across a circuit of constant resistance is doubled, how is the current in the circuit affected? The current is quadrupled. The current is reduced by a factor of 2. The current is doubled. The current remains constant. The current is reduced by a factor of 4.

If the resistance in a circuit connected to a constant current is halved, how is the voltage in the circuit affected? The voltage remains constant. The voltage is doubled. The voltage is reduced by a factor of 4. The voltage is reduced by a factor of 2. The voltage is quadrupled.

A constant voltage is applied across a circuit. If the resistance in the circuit is doubled, what is the effect on the power dissipated by the circuit? The power dissipated is quadrupled. The power dissipated remains constant. The power dissipated is doubled. The power dissipated is reduced by a factor of 4. The power dissipated is reduced by a factor of 2.

A circuit maintains a constant resistance. If the current in the circuit is doubled, what is the effect on the power dissipated by the circuit? The power dissipated is doubled. The power dissipated is quadrupled. The power dissipated is reduced by a factor of 2. The power dissipated remains constant. The power dissipated is reduced by a factor of 4.

What happens to the resistance of most common metals as the temperature of the metal increases? The resistance remains constant as temperature increases. The resistance decreases as temperature increases. Whether resistance increases or decreases as temperature increases depends on the type of metal. The resistance increases as temperature increases.

As more resistors are added in parallel across a constant voltage source, the power supplied by the source does not change. decreases. increases.

Which of the following statements are true? Earth's geographic south pole is also a magnetic south pole. The south poles of two bar magnets will repel each other. The north poles of two bar magnets will attract each other. Scientists have evidence that single isolated magnetic poles, called magnetic monopoles, exist. Earth's geographic north pole is actually a magnetic south pole. The north pole of a bar magnet will attract the south pole of another bar magnet.

Consider a magnetic force acting on an electric charge in a uniform magnetic field. Which of the following statements are true? An electric charge moving perpendicular to a magnetic field experiences a magnetic force. A magnetic force is exerted on a stationary electric charge in a uniform magnetic field. The direction of the magnetic force acting on a moving electric charge in a magnetic field is perpendicular to the direction of motion. A magnetic force is exerted on an electric charge moving through a uniform magnetic field. An electric charge moving parallel to a magnetic field experiences a magnetic force. The direction of the magnetic force acting on a moving charge in a magnetic field is perpendicular to the direction of the magnetic field.

An electron is traveling horizontally toward the north in a uniform magnetic field that is directed vertically downward. In what direction does the magnetic force act on the electron? south east west north upward downward

A charged particle enters into a uniform magnetic field such that its velocity vector is perpendicular to the magnetic field vector. Ignoring the particle's weight, what type of path will the particle follow? The charged particle will follow a circular path. The charged particle will follow a parabolic path. The charged particle will follow a straight-line path. The charged particle will follow a spiral path.

Which of the following statements are true for magnetic force acting on a current-carrying wire in a uniform magnetic field? The direction of the magnetic force acting on a current-carrying wire in a uniform magnetic field is perpendicular to the direction of the field. The magnetic force on the current-carrying wire is strongest when the current is perpendicular to the magnetic field lines. The direction of the magnetic force acting on a current-carrying wire in a uniform magnetic field is perpendicular to the direction of the current. The magnetic force on the current-carrying wire is strongest when the current is parallel to the magnetic field lines.

The magnitude of the magnetic field at a certain distance from a long, straight conductor is represented by B. What is the magnitude of the magnetic field at twice the distance from the conductor? At twice the distance, the magnitude of the field remains equal to B. At twice the distance, the magnitude of the field is 2B. At twice the distance, the magnitude of the field is B/4. At twice the distance, the magnitude of the field is B/2. At twice the distance, the magnitude of the field is 4B.

Two long parallel wires are placed side by side on a horizontal table. The wires carry equal currents in the same direction. Which of the following statements are true? The magnetic force between the two wires is attractive. The magnetic field is a maximum at a point midway between the two wires. The magnetic field at a point midway between the two wires is zero. The magnetic force between the two wires is repulsive.

Two very long parallel wires are a distance d apart and carry equal currents in opposite directions. The locations where the net magnetic field due to these currents is equal to zero are a distance d/2√ to the left of the left wire and also a distance d/2√ to the right of the right wire. a distance d to the left of the left wire and also a distance d to the right of the right wire. midway between the wires. a distance d/2 to the left of the left wire and also a distance d/2 to the right of the right wire. The net field is not zero anywhere.