REVIEW SESSION 1 FOR THE FINAL EXAM Prof. Flera Rizatdinova

Summary of Chapter 16

•  Two kinds of electric charge—positive and negative

•  Charge is conserved

•  Charge on electron: e = 1.602 × 10−19 C

•  Conductors: electrons free to move

•  Insulators: nonconductors

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Summary of Chapter 16

•  Charge is quantized in units of e

•  Objects can be charged by conduction or induction

•  Coulomb’s law:

•  Electric field is force per unit charge:

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(16-3)

(16-1)

Summary of Chapter 16

•  Electric field of a point charge:

•  Electric field can be represented by electric field lines

•  Static electric field inside conductor is zero; surface field is perpendicular to surface

•  Electric flux:

•  Gauss’s law:

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(16-4a)

(16-7)

(16-9)

•  Electric potential is potential energy per unit charge:

•  Electric potential difference: work done to move charge from one point to another

•  Relationship between potential difference and field:

Summary of Chapter 17

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(17-2a)

(17-4a)

Summary of Chapter 20

•  Magnets have north and south poles

•  Like poles repel, unlike attract

•  Unit of magnetic field: tesla

•  Electric currents produce magnetic fields

•  A magnetic field exerts a force on an electric current:

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Summary of Chapter 20

•  A magnetic field exerts a force on a moving charge:

•  Magnitude of the field of a long, straight current-carrying wire:

•  Parallel currents attract; antiparallel currents repel

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Summary of Chapter 20

•  Magnetic field inside a solenoid:

•  Ampère’s law:

•  Torque on a current loop:

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•  Equipotential: line or surface along which potential is the same

•  Electric potential of a point charge:

•  Electric dipole potential drops off as 1/r2

Summary of Chapter 17

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(17-5)

•  Capacitance:

•  Capacitance of a parallel-plate capacitor:

•  Energy density in electric field

Summary of Chapter 17

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(17-7)

(17-8)

(17-11)

Summary of Chapter 18

•  A battery is a source of constant potential difference.

•  Electric current is the rate of flow of electric charge.

•  Conventional current is in the direction that positive charge would flow.

•  Resistance is the ratio of voltage to current:

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Summary of Chapter 18

•  Ohmic materials have constant resistance, independent of voltage.

•  Resistance is determined by shape and material:

•  ρ is the resistivity.

•  Power in an electric circuit:

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Summary of Chapter 18

•  Direct current is constant

•  Alternating current varies sinusoidally

•  The average (rms) current and voltage:

•  The average (rms) current and voltage:

Summary of Chapter 19

•  A source of emf transforms energy from some other form to electrical energy

•  A battery is a source of emf in parallel with an internal resistance

•  Resistors in series:

•  Resistors in parallel:

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Summary of Chapter 19

•  Capacitors in parallel:

•  Capacitors in series:

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Problems

  At each corner of a square of side l there are point charges of magnitude Q, 2Q, 3Q and 4Q. Determine the magnitude and direction of the force on the charge 2Q.

  Determine (a) the equivalent resistance of the cicuit, (b) the voltage across each resistor, and (c) the current through each resistor.

Summary of Chapter 20

•  Magnets have north and south poles

•  Like poles repel, unlike attract

•  Unit of magnetic field: tesla

•  Electric currents produce magnetic fields

•  A magnetic field exerts a force on an electric current:

© 2014 Pearson Education, Inc.

Summary of Chapter 20

•  A magnetic field exerts a force on a moving charge:

•  Magnitude of the field of a long, straight current-carrying wire:

•  Parallel currents attract; antiparallel currents repel

© 2014 Pearson Education, Inc.

Summary of Chapter 20

•  Magnetic field inside a solenoid:

•  Ampère’s law:

•  Torque on a current loop:

© 2014 Pearson Education, Inc.

Summary of Chapter 21

•  Magnetic flux:

•  Changing magnetic flux induces emf:

•  Induced emf produces current that opposes original flux change

•  Changing magnetic field produces an electric field

•  Electric generator changes mechanical energy to electrical energy; electric motor does the opposite

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Summary of Chapter 21

•  Transformer uses induction to change voltage:

•  Mutual inductance:

•  Energy density stored in magnetic field:

•  LRC series circuit:

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Problems

  A helium ion (Q=+2e) whose mass is 6.6×10-27 kg is accelerated by a voltage of 3700 V. (a) What is its speed? (b) What is its radius of curvature if it moves in a plane perpendicular to a uniform magnetic field B=0.34 T?

  The moving rod has a resistance of 0.25Ω and moves on rails 20 cm apart. When a force of 0.35 N is applied to the rod, it moves to the right at a constant speed of 1.5 m/s. What is the magnetic field B?