Physics Chapter 19 test

A current in a solenoid with N turns creates a magnetic field at the center of that loop.The field strength is directly proportional to:

A. number of turns in the loop B. current strength

The direction of the force on a current carrying wire located in an external magnetic field is which of the following?

A. perpendicular to the current B. perpendicular to the field

The force on a charged particle created by its motion in a magnetic field is maximum at what angle between the particle velocity and field?

C. 45

Electrical charges and magnetic poles have many similarities, but one difference is:

D. A magnetic pole cannot be isolated.

When a magnetic field causes a charged particle to move in a circular path, the only quantity listed below which the magnetic force changes significantly as the particle goes around in a circle is the particle's:

momentum

Right Hand rule

qv = thum

Consider two long, straight parallel wires, each carrying a current I. If the currents are flowing in opposite directions:

A. The two wires will repel each other.

If a charged particle is moving in a uniform magnetic field, its path can be

A. a straight line. B. a circle. C. ahelix.

The term magnetic declination refers to which of the following?

A. angle between directions to true north and magnetic north

A current in a solenoid coil creates a magnetic field inside that coil.The field strength is directly proportional to:

A. current

The magnetic field of the Earth is believed responsible for which of the following?

A. deflection of charged cosmic rays

The current in a long wire creates a magnetic field in the region around the wire. How is the strength of the field at distance r from the wire center related to the magnitude of the field?

A. field inversely proportional to r

The force exerted on a current-carrying wire located in an external magnetic field is directly proportional to which of the following?

A. field strength B. current strength

A current in a long, straight wire produces a magnetic field.The magnetic field lines:

A. form circles that go around the wire

A proton is released such that its initial velocity is from right to left across this page.The proton's path, however, is deflected in a direction toward the bottom edge of the page due to the presence of a uniform magnetic field.What is the direction of this field?

A. into the page

The units for charge are amperes.

False

A stationary charged particle will experience a force when placed in a magnetic field.

False

The split ring contacts in a motor are called the armature for a motor.

False

The units for magnetic field are Electron Volts.

False

When a moving charge particle is placed in a magnetic field so that the velocity is perpendicular to the field the resulting motion will be a helical path.

False

When trying to find the direction of the force produced by a magnetic field on a moving electron you use the left hand rule.

False

A magnetic field can never do work on a moving charged particle.

True

A solenoid can also be called an electromagnet.

True

A solenoid will act like a bar magnet having a north and south pole.

True

Magnetic field lines in a bar magnet are directed out of the north pole and into the south pole of the magnet.

True

The needle of a compass will point in a direction parallel to the magnetic field lines.

True

Geophysicists today generally attribute the existence of the Earth's magnetic field to which of the following?

B. convection currents within the liquid interior

A proton moves across the Earth's equator in a easterly direction. At this point the Earth's magnetic field has a direction due north and is parallel to the surface.What is the direction of the force acting on the proton at this instant?

B. into the Earth's surface

In a mass spectrometer, an ion will have a smaller radius for its circular path if

B. its charge is greater

Two insulated current-carrying straight wires of equal length are arranged in the lab so that Wire A carries a current northward and Wire B carries a current eastward, the wires crossing at their midpoints separated only by their insulation. Which of the following statements are true?

D. There are forces, but the net force on each wire is zero.

Right Hand Rule

Predicts direction of current in a wire when it moves relative to a magnetic field

The path of a charged particle moving parallel to a uniform magnetic field will be:

straight line